|description=The 3525 is the first Oyster chronograph. That is why it matters. Everything from the 6034 through the Daytona sits downstream of that move.
|description=What auction records show about Rolex’s early Oyster chronograph: its one-piece upper case, Valjoux-based movement, dial examples and wartime deliveries.
The 3525 is Rolex's first Oyster chronograph. Earlier Rolex chronographs existed, but none in a screw-down Oyster case. That makes the 3525 the technical starting point for the later 6034, 6238, and Daytona line. Collectors call it ''Monoblocco'' for the one-piece upper case and ''Barilotto'' for its barrel-like profile.
Auctioneers often call the 3525 Rolex’s first chronograph in an Oyster case. That description usually refers to the two-pusher branch: earlier Oyster-cased monopushers, refs. 3346 and 3462, came first, according to Colin White’s ''The Vintage Rolex Field Manual''. The 3525 is a two-pusher, two-register watch, made in steel and gold variants. Its upper case is one piece; the screw-down back is separate. Auction catalogues place examples from around 1939 to the mid-1940s, but do not establish a complete production span.
It is also the watch that Rolex shipped, on credit, to Allied officers held in German prisoner-of-war camps during the Second World War. One of those watches ended up at Stalag Luft III, the camp of the Great Escape. That example, with its paperwork fully intact, sold at Antiquorum in 2007.
<span id="core-facts"></span>
== Core facts ==
==Core facts==
{| class="wikitable rp-facts"
{| class="wikitable rp-facts"
Line 35:
Line 26:
| 3525
| 3525
|-
|-
| family
| line
| Chronograph (pre-Daytona)
| Oyster chronograph; pre-Daytona
|-
|-
| production
| documented dates
| 1939–1945
| Examples catalogued from circa 1940 to circa 1945; factory start and end dates are not established here
|-
|-
| case diameter
| case
| ~35mm
| About 35 mm in cited auction descriptions; one-piece upper case and screw-down back
|-
|-
| case construction
| materials
| ''Monoblocco'' — one-piece upper case (bezel + mid-case + lugs) plus screw-down caseback
| Stainless steel, pink gold, yellow gold and steel/gold examples are catalogued
Rolex patented the Oyster case in 1926 and the Perpetual rotor in 1931–32. By the late 1930s the Oyster had become standard across the range of time-only and time-plus-date watches, but it had not yet accommodated a chronograph. The obstacle was obvious: chronograph movements need pushers, pushers breach the case, and a breached case is not waterproof. The 3525 answers that problem with screw-down pushers, a screw-down caseback, and a case whose upper half — the part that carries the pushers, the crystal seat, and the crown tube — is machined from a single billet of metal, eliminating the jointed seams a multi-piece construction would otherwise present to water.
Auction houses describe the 3525 as the first Rolex chronograph fitted in a waterproof Oyster case. The claim needs a qualifier: the earlier Centregraph refs. 3346 and 3462 were Oyster-cased monopusher chronographs, as listed in Colin White’s ''The Vintage Rolex Field Manual''. The 3525 belongs to the later two-pusher, two-register branch. “First two-pusher Oyster chronograph” is a safer short description than “first Oyster chronograph.”
In the surrounding catalogue, the 3525 is the first of the Oyster chronographs. Its sister reference 3668, produced in tiny numbers in the 1940s with a reeded gold bezel, carries the same Cal. 23 VZ base in a different case construction. The 4500 of the late 1940s introduces the tonneau case, and the 6034 in the early 1950s finally adopts the screw-down pusher architecture the 3525 foreshadowed. As the first Rolex chronograph to enter an Oyster case, the 3525 is the pivot.
The later reference 6034 is not the first to use screw-down pushers. It has pump pushers like the 3525; Rolex introduced screw-down chronograph pushers on the Daytona ref. 6240 in 1965. The 3525’s crown and caseback screw down, while the chronograph buttons remain ordinary round pushers.
Sotheby’s [https://www.sothebys.com/en/buy/auction/2020/important-watches-part-ii/monoblocco-ref-3525-stainless-steel-chronograph 2020 catalogue] describes the upper case, bezel and lugs as one piece, with a separate screw-down caseback. That construction is the source of the collector name “Monoblocco.” Auction catalogues give a diameter of 35 mm for several examples. Those measurements belong to the listed watches; they do not establish one exact dimension for every case.
The ''Monoblocco'' construction is the technical centerpiece of the reference. On a conventional three-piece Oyster, the case is made up of a bezel that screws onto the mid-case, the mid-case itself, and a caseback that screws in from below. Each interface between pieces is a potential water path sealed with a gasket. On the 3525, the bezel, the mid-case and the lugs are not separate pieces. They are one piece of metal, turned and machined as a unit. Only the caseback threads in separately. The crown and the two chronograph pushers pass through the single upper piece, each with its own screw-down seal.
The Nutting and Brownlee catalogues describe round-button pushers. Neither source describes screw-down pushers. A crown that screws into the case and a screw-down back are part of the Oyster arrangement; they should not be conflated with the chronograph buttons.
Italian collectors called the construction ''Monoblocco'' from early on. The alternative nickname, ''Barilotto'', comes from the barrel-like taper of the upper case in profile — the bezel zone is slightly narrower than the caseback perimeter, giving the watch a faintly hourglass shape in side view. Both names appear interchangeably in Papaleo, Pucci, and Mondani, and in modern catalog text from Antiquorum and Sotheby's.
==Movement and display==
The case measures about 35 mm across. That was a full-sized men's chronograph in period, and on the wrist today it wears small. The lug-to-lug is short, the crystal domed acrylic, the whole package lighter and thinner than anything from the Daytona era. Next to a Cosmograph Daytona of the 6239 generation, the 3525 reads as noticeably more restrained and unmistakably of its period.
Auction descriptions connect the 3525 with Rolex Cal. 13 and the Valjoux 23 family. Antiquorum’s [https://catalog.antiquorum.swiss/en/lots/rolex-lot-163-311 Nutting catalogue] lists a 13-ligne, 17-jewel movement; Sotheby’s 2020 lot gives manual winding and 17 jewels without naming the caliber. The [https://catalog.antiquorum.swiss/en/lots/rolex-ref-3525-monoblocco-lot-360-319 Brownlee catalogue] names Cal. 13. Taken together, these support the Cal. 13 / Valjoux 23-family attribution, while the exact suffix and finishing should be checked against the movement in a specific watch.
<span id="the-cal.-13-and-the-valjoux-23"></span>
The cited watches have two subsidiary registers and a central chronograph hand. The Nutting catalogue describes subsidiary seconds and a 30-minute register, plus tachometer and telemeter scales. Other catalogue records describe different dial layouts or omit scale details. Do not treat one auction description as a complete dial specification for the reference.
== The Cal. 13 and the Valjoux 23 ==
Rolex catalogued the movement as "Cal. 13." The designation refers to the 13-ligne size (roughly 29.5mm) of the movement blank. The base is the Valjoux 23 VZ, a lateral-clutch, column-wheel chronograph with 17 jewels, a running seconds register at 9 o'clock and a 30-minute counter at 3 o'clock. No continuous hour counter; the 3525 is a two-register watch. Central chrono seconds. The balance is screwed; the bridges carry "Rolex" and "17 Rubis" signatures in most examples.
==Dial and case variants==
The Valjoux 23 was one of the most respected chronograph bases of the 1930s and 1940s, used by Patek Philippe, Vacheron Constantin, Breguet, and others. Rolex bought the base from Valjoux, finished it, and housed it. The "in-house" framing occasionally applied to Rolex chronographs of this era is inaccurate for the 3525: Rolex did not manufacture the chronograph module; it specified, finished, and cased it.
The surviving catalogue sample includes silvered, black and pink dials on steel and gold watches. Sotheby’s [https://www.sothebys.com/en/auctions/ecatalogue/2019/important-watches-n10082/lot.183.html 2019 steel example] is described as black gilt; its [https://www.sothebys.com/en/buy/auction/2020/important-watches-part-ii/monoblocco-ref-3525-stainless-steel-chronograph 2020 steel example] has a silvered dial. Antiquorum’s [https://catalog.antiquorum.swiss/en/lots/rolex-lot-108-128 1940 pink-gold Mondani example] has a matte pink dial. This small sample does not establish which dial was most common, metal-to-dial pairings across the full run, or a premium for tropical examples.
The movement's configuration sets the reading logic of the dial. Elapsed minutes read at 3 o'clock. Running seconds read at 9 o'clock. Elapsed seconds read off the central hand. The outer chapter carries a tachometer scale for speed calculation and a telemeter scale for distance-to-sound-source calculation. Both scales were standard period equipment on a sports chronograph, and both persist through the Daytona era that follows.
[[File:Ref_3525_dial-side.webp|thumb|right|240px|alt=Side view of the dial and case of a Rolex 3525|Dial and case profile.]]
<span id="dial-variants"></span>
==Wartime orders==
== Dial variants ==
[[File:Ref 3525 dial-side.jpg|thumb|right|280px|alt=3525 dial side profile|3525 dial side profile]]
Rolex allowed some prisoners of war to order watches and defer payment until after the war. Antiquorum’s [https://catalog.antiquorum.swiss/en/lots/rolex-lot-163-311 2007 Nutting lot] lists a receipt dated 8 July 1943, an order acknowledgement, a dispatch note, a guarantee and correspondence with Hans Wilsdorf. The catalogue says the watch was “sold gratis”; a 1948 letter in the archive gives the balance as £15 12s 6d.
Across roughly six years of production and four case metals, the 3525 accumulated a full range of dial configurations.
Nutting was a Royal Corps of Signals corporal held at Stalag Luft III. The catalogue records that he ordered the watch in March 1943 and kept papers and photographs from the camp. The watch is associated with the Great Escape because it was at the camp before the March 1944 breakout; no cited document shows that Nutting used its chronograph to time the escape. The archived catalogue gives an estimate of CHF 130,000–160,000 and shows no hammer price; the often-circulated £66,000 result is unsupported by that record.
The silvered dial is the most common configuration on stainless steel cases, with applied baton or Arabic indexes, blued steel hands, and printed tachometer and telemeter scales on the outer track. The Sotheby's 2020 Important Watches Part II example (case 372,822, c.1945) carries it. Glossy black gilt — black with gilt (gold-toned) printing for scales and signatures — is the other principal steel dial; the Sotheby's 2019 example (case 186,144, c.1942) is described in the lot text as "glossy black gilt," tracking the same gilt-printing convention Rolex used on contemporary time-only Oysters before the matte-dial transition of the mid-1960s.
Antiquorum’s [https://catalog.antiquorum.swiss/en/lots/rolex-ref-3525-monoblocco-lot-360-319 2023 catalogue] documents a second example, case 185985, delivered to USAAF first lieutenant Leon W. Brownlee, who was held at Stalag VII-A. Phillips has published a separate account of RAF officer Douglas S. Dickins and a 3525. These are individual provenance records; they do not establish the number of watches Rolex sent to camps or a complete “POW” production variant.
Salmon or pink matte dials are standard on pink gold cases. The Mondani Collection example (case 147,854, 1940) carries a matte pink dial with printed baton indexes, Arabic 6 and 12, and blued steel baton hands. Two-tone dials combine contrasting center and outer chapter in the Art Deco dial language common to late-1930s and early-1940s chronographs.
==Serial numbers and dating==
Tropical black dials are original black dials that have shifted to brown under UV exposure. As with later Submariner and GMT-Master gilt dials, tropical 3525 dials command a substantial premium when the fade is even and the printing remains crisp. Military-spec black — matte black with applied luminous markers — is the configuration that appears on the POW-delivered examples; the Nutting and Brownlee watches both carry black dials, though whether the black dial was specified by the recipient, selected by Rolex for the POW program, or simply the stock option for the steel 3525 in the early 1940s is not documented.
Sotheby’s [https://www.sothebys.com/en/buy/auction/2020/important-watches-part-ii/monoblocco-ref-3525-stainless-steel-chronograph 2020 catalogue] divides its examples into two case-marking groups: an earlier series with reference and serial on the outside of the caseback, and a later series with the reference inside and the serial between the lugs. It dates those groups broadly to 1939–42 and 1942–46. These are auction-house dating conventions. A serial number alone does not establish when a watch was made or delivered; compare the markings and original paperwork on the specific example. See the [[Reference:Serial-numbers|serial-number guide]].
The 3525's second identity is as the "POW watch," the Rolex chronograph that Hans Wilsdorf shipped to Allied officers in German prisoner-of-war camps during the Second World War.
Selected catalogue entries. Estimates are not results; where a public result is unavailable, it is stated as such.
The mechanism was simple enough: British and Commonwealth POWs could still order watches by mail, Rolex could still ship from neutral Switzerland, and Wilsdorf let them pay after the war. The point is not the romance, but that the watches were sold on extended credit, not simply handed out.
The best-documented example is the Nutting watch. Corporal Clive James Nutting of the British Army was captured and interned at Stalag Luft III, the German Luftwaffe-run prison camp in Lower Silesia (today Żagań, Poland) — the Great Escape camp, where 76 POWs broke out of Hut 104 through a tunnel in March 1944, as later dramatized in the 1963 film. Nutting was a shoemaker by trade and a signals specialist, on the escape-planning committee from early on. He did not use the tunnel himself before its discovery, but he made civilian belts, shoes, and briefcases for escapers from leather stolen from German officers who had brought their kit in for repair.
Nutting ordered a Rolex. The watch is a steel 3525 Oyster Chronograph Antimagnetic, serial 185,983, made in 1941 and shipped by Rolex on credit in 1943. The Antiquorum lot text records a shipping date of 8 July 1943; Rolex Magazine's article on the watch records a delivery-to-camp date of 4 August 1943. Both can be true: one is the Swiss ship date, the other the camp arrival date. By August 1943 Nutting had a Rolex chronograph on his wrist in Stalag Luft III, eight months before the Great Escape.
Nutting kept the watch for the rest of his life. He repatriated to Britain after the war, later emigrated to Queensland, Australia, and died there in 2001 at age 90. His archive stayed with the watch: the numbered receipt from Rolex, the numbered guarantee, the Rolex envelope, three letters from the Rolex Watch Co. signed by Hans Wilsdorf, and Nutting's own correspondence and photographs from Stalag Luft III. The whole package sold at Antiquorum in 2007 for £66,000.
Other POW-provenance 3525s surface periodically. The Brownlee watch (USAAF 1st Lt Leon W. Brownlee, held at Stalag 7A in Moosburg, Bavaria, freed April 1945) appeared at Antiquorum Geneva in May 2023 with an estimate of EUR 62,000–102,000. Phillips published an article on the Dickins 3525 (RAF Wing Commander Douglas S. Dickins). Dealer and forum listings carry additional named-POW examples. The Rolex POW archive is incomplete; no full list of delivered watches survives in public. The documented examples form a small, coherent corpus.
On the specific claim that the Nutting 3525 was used to time the Great Escape itself: Nutting was on the planning committee, the 3525 is a chronograph with a 30-minute counter, and the watch was on his wrist in the camp at the right time. Whether it was actually used to time guard patrols or to cue escapees through the tunnel is not documented in the Rolex archive or in Nutting's own writings. The connection is circumstantial, strong enough to mention but not to state as fact.
<span id="auction-record"></span>
== Auction record ==
The 3525 appears regularly at major auction houses. A representative set of lots:
{| class="wikitable"
{| class="wikitable"
|-
|-
! Venue
! Venue and date
! Date
! Lot / case
! Case No
! Catalogue description
! Material
! Estimate or result
! Dial
! Notes
! Result / Estimate
|-
| Antiquorum Geneva (Mondani Collection)
| 14 May 2006
| 147854
| 18K pink gold
| Matte pink, bâtons
| Illustrated in Mondani
| —
|-
|-
| Antiquorum Geneva
| [https://catalog.antiquorum.swiss/en/lots/rolex-lot-163-311 Antiquorum, Geneva, 13 May 2007]
| 2007
| 311 / 185983
| 185983
| Nutting watch; steel; 17-jewel movement; original receipt, guarantee and Wilsdorf correspondence
| Stainless steel
| Estimate CHF 130,000–160,000; result not shown on archived page
| Black
| Nutting POW, full archive, Wilsdorf letters
| '''£66,000'''
|-
|-
| Antiquorum New York
| [https://catalog.antiquorum.swiss/en/lots/rolex-lot-108-128 Antiquorum, Geneva, 14 May 2006]
| Steel, circa 1945; silvered dial; 35 mm; 17 jewels
| Stainless steel
| Estimate CHF 20,000–30,000; result not shown
| Black gilt (glossy)
| Rivet bracelet; c.1942
| Est. USD 12,000–18,000
|-
|-
| Sotheby's (Important Watches Part II)
| [https://catalog.antiquorum.swiss/en/lots/rolex-ref-3525-monoblocco-lot-360-319 Antiquorum, Geneva, 15 May 2023]
| 2020
| 319 / 185985
| 372822
| Brownlee watch; steel; circa 1941; Cal. 13; 35 mm
| Stainless steel
| Estimate CHF 60,000–100,000; result not recorded here
| Silvered
| c.1945, second production series
| Est. CHF 20,000–30,000
|-
| Antiquorum Geneva
| May 2023
| —
| Stainless steel
| Black
| Brownlee POW, USAAF Stalag 7A
| Est. EUR 62,000–102,000
|-
| Antiquorum Geneva
| May 2024
| 47267
| 18K pink gold
| Black
| Monoblocco
| Est. USD 89,000–156,000
|-
| Antiquorum Hong Kong
| 1 Jun 2024
| —
| 18K pink gold
| —
| Retailed by Verga
| Est. CHF 82,000–140,000
|}
|}
The price spread tracks two primary variables: metal and provenance. A plain-dial steel example without special provenance trades in the low five figures USD; a pink gold example trades in the high five to low six figures; and a fully provenanced POW example with Wilsdorf correspondence clears six figures. The Nutting watch at £66,000 in 2007 remains the anchor result for the reference, and that figure would clear multiples today, both because the market has moved and because the corpus of comparable paperwork-intact POW provenance has not grown.
This is a small, selected set of catalogue records, not a census or a current price guide. Auction descriptions and dating are attributed to the sale house.
File:Ref_3525_hero.webp|alt=Rolex 3525 Monoblocco chronograph|Steel 3525, front view
File:Ref_3525_dial-side.webp|alt=Side view of the dial and case of a Rolex 3525|Dial and case profile
</gallery>
Case numbers observed on documented 3525s span from the ~140,000s (1940) through the ~370,000s (1945). That range is broad because the 3525 was produced continuously for six years, shared serial allocations with other Rolex references of the period, and included multiple metal variants produced at different cadences. The Sotheby's 2020 lot text describes a "second production series (1942–1946)" for case 372,822, a distinction that suggests two generations of 3525, potentially with minor detail changes between early and late production. Specialist research on the precise transition point has not been published in accessible sources.
== Sources ==
The Alpha Hands 3525 Case Number Project aggregates documented serials in a searchable database. Its working estimate for total production exceeds the older dealer-literature figure of ~200 steel examples; actual steel production is likely in the low four figures, with gold examples adding several hundred more. A reasonable working total across all metals is ~2,000–2,500 pieces. Firm archival documentation does not exist.
<span id="authentication-notes"></span>
== Authentication notes ==
The 3525 is old enough that condition and originality variance is extreme. A buyer's checklist on period-correct examples:
Case geometry. The Monoblocco construction should be visible in profile: no interior seam where a bezel would meet a separate mid-case. The caseback is the only separable part. Pushers should be flat round buttons that screw down; unscrewed, they should rotate smoothly and spring back firmly.
Caseback markings. The inside of the caseback on a period-correct 3525 carries Rolex-specific stamping including "Oyster Watch Co" and period reference and model codes. Over-polished casebacks with the stamping worn away are common after 80 years of ownership.
* [https://catalog.antiquorum.swiss/en/lots/rolex-lot-108-128 Antiquorum, ref. 3525, case 147854, Geneva, 14 May 2006]
Dial. Refinished and replacement dials are the single largest originality variable on vintage 3525s. Period-correct printing on the tachometer and telemeter scales is fine and crisp; heavy, thick printing is a refinish indicator. Applied indexes on gold cases should match the case metal tone. Black gilt dials with even patina and intact gilt printing carry substantial premiums; the same dial refinished is worth a fraction.
* [https://catalog.antiquorum.swiss/en/lots/rolex-ref-3525-monoblocco-lot-360-319 Antiquorum, Leon W. Brownlee’s ref. 3525, Geneva, 15 May 2023]
* [https://www.sothebys.com/en/auctions/ecatalogue/2019/important-watches-n10082/lot.183.html Sotheby’s, ref. 3525, case 186144, 2019]
Movement. Cal. 13 (Valjoux 23 VZ) should be signed on the bridges. Movement serials should sit in the documented range. Replacement movements transplanted from a non-Rolex Valjoux 23 host exist; the movement bridges should read "Rolex," not "Valjoux."
* [https://www.sothebys.com/en/buy/auction/2020/important-watches-part-ii/monoblocco-ref-3525-stainless-steel-chronograph Sotheby’s, ref. 3525, case 372822, 2020]
* [https://www.phillips.com/article/122074426/rolex-chrono-3525-wwii-pow-raf-dickens Phillips, Douglas S. Dickins and his ref. 3525, 2023]
Provenance paperwork. For any 3525 offered with POW provenance, the physical documentation is decisive. Wilsdorf letters on period Rolex letterhead, numbered guarantee, numbered receipt, and POW archive material collectively make the provenance. Verbal family-lore provenance without paperwork is treated with skepticism in the market.
* Colin A. White, ''The Vintage Rolex Field Manual'', entries for refs. 3346, 3462 and 3525.
<span id="what-the-3525-established"></span>
== What the 3525 established ==
Two features of the 3525 persist in Rolex chronograph production for decades after the reference itself ends.
The first is the Oyster chronograph case itself. Every Rolex chronograph after the 3525 is waterproof: the 3668, 4500, 6034, 6234, 6238, and the Daytona family all descend from the waterproofing solution the 3525 solved first. The specific ''Monoblocco'' construction does not persist — by the 6034 generation Rolex is using multi-piece Oyster cases with screw-down pushers — but the principle does.
The second is the sport-chronograph identity. The 3525 is a chronograph with a purpose rather than a dress complication: tachometer and telemeter scales, screw-down crown, screw-down pushers, 17-jewel lateral-clutch movement, rivet Oyster bracelet as the period-correct strap choice. That package, a functional chronograph designed to be worn hard, is what runs straight through to the Paul Newman Daytona and beyond.
<span id="collecting-considerations"></span>
== Collecting considerations ==
The 3525 occupies a specific place in the vintage Rolex market. Compared with a Daytona, prices are lower, the collector pool is smaller, and the academic literature is thinner. Compared with a generic 1940s chronograph, the Oyster construction, the POW history and the Rolex signature carry a meaningful premium.
Metal matters first. Steel 3525s are the most historically significant — most POW examples are steel — and the most commonly encountered. Pink gold is the dress-watch alternative and commands substantial premiums, with yellow gold sitting between. Steel-plus-gold two-tone examples are the rarest configuration and trade inconsistently.
POW provenance is a category of its own. A paperwork-backed POW 3525 is effectively a different watch from a civilian-delivered 3525 of the same specification, and the price gap can be 5–10x. This is a market where documentation is doing enormous work, and the documentation must be convincing.
After metal and provenance, dial originality is the biggest variance driver. Untouched original dials with even patina command multiples of refinished or replacement dials. For the black gilt variant specifically, the fade pattern and gilt printing intactness are the primary inspection points.
Service history matters at 80+ years. A 3525 that has been serviced periodically is in better mechanical shape than one that has not, but heavy service can also mean replaced mainsprings, replaced chrono coupling parts, and in some cases replaced movement components. Known service history from a reputable vintage Rolex watchmaker adds value.
<span id="related-references"></span>
== Related references ==
The 3525 is the first Oyster chronograph and the centrepiece of the [[Reference:pre-daytona-chronographs|pre-Daytona chronograph]] line. The Monoblocco case work and Cal. 13 (Valjoux 23 VZ) movement set the template for the 4xxx tonneau Oyster chronographs that followed.
== Sources ==
* [https://catalog.antiquorum.swiss/ Antiquorum — 3525 nutting 2007]
Auctioneers often call the 3525 Rolex’s first chronograph in an Oyster case. That description usually refers to the two-pusher branch: earlier Oyster-cased monopushers, refs. 3346 and 3462, came first, according to Colin White’s The Vintage Rolex Field Manual. The 3525 is a two-pusher, two-register watch, made in steel and gold variants. Its upper case is one piece; the screw-down back is separate. Auction catalogues place examples from around 1939 to the mid-1940s, but do not establish a complete production span.
Core facts
detail
value
reference
3525
line
Oyster chronograph; pre-Daytona
documented dates
Examples catalogued from circa 1940 to circa 1945; factory start and end dates are not established here
case
About 35 mm in cited auction descriptions; one-piece upper case and screw-down back
materials
Stainless steel, pink gold, yellow gold and steel/gold examples are catalogued
movement
Rolex Cal. 13 is associated with a Valjoux 23-family movement; catalogue descriptions vary in detail
display
Two registers and central chronograph seconds; individual catalogues describe different dial scales and details
pushers
Round pump pushers; they do not screw down
collector term
“Monoblocco,” for the one-piece upper case; “Barilotto” appears in collector writing but is less consistently sourced
Where it sits in the line
Auction houses describe the 3525 as the first Rolex chronograph fitted in a waterproof Oyster case. The claim needs a qualifier: the earlier Centregraph refs. 3346 and 3462 were Oyster-cased monopusher chronographs, as listed in Colin White’s The Vintage Rolex Field Manual. The 3525 belongs to the later two-pusher, two-register branch. “First two-pusher Oyster chronograph” is a safer short description than “first Oyster chronograph.”
The later reference 6034 is not the first to use screw-down pushers. It has pump pushers like the 3525; Rolex introduced screw-down chronograph pushers on the Daytona ref. 6240 in 1965. The 3525’s crown and caseback screw down, while the chronograph buttons remain ordinary round pushers.
Case and crown
Sotheby’s 2020 catalogue describes the upper case, bezel and lugs as one piece, with a separate screw-down caseback. That construction is the source of the collector name “Monoblocco.” Auction catalogues give a diameter of 35 mm for several examples. Those measurements belong to the listed watches; they do not establish one exact dimension for every case.
The Nutting and Brownlee catalogues describe round-button pushers. Neither source describes screw-down pushers. A crown that screws into the case and a screw-down back are part of the Oyster arrangement; they should not be conflated with the chronograph buttons.
Movement and display
Auction descriptions connect the 3525 with Rolex Cal. 13 and the Valjoux 23 family. Antiquorum’s Nutting catalogue lists a 13-ligne, 17-jewel movement; Sotheby’s 2020 lot gives manual winding and 17 jewels without naming the caliber. The Brownlee catalogue names Cal. 13. Taken together, these support the Cal. 13 / Valjoux 23-family attribution, while the exact suffix and finishing should be checked against the movement in a specific watch.
The cited watches have two subsidiary registers and a central chronograph hand. The Nutting catalogue describes subsidiary seconds and a 30-minute register, plus tachometer and telemeter scales. Other catalogue records describe different dial layouts or omit scale details. Do not treat one auction description as a complete dial specification for the reference.
Dial and case variants
The surviving catalogue sample includes silvered, black and pink dials on steel and gold watches. Sotheby’s 2019 steel example is described as black gilt; its 2020 steel example has a silvered dial. Antiquorum’s 1940 pink-gold Mondani example has a matte pink dial. This small sample does not establish which dial was most common, metal-to-dial pairings across the full run, or a premium for tropical examples.
Dial and case profile.
Wartime orders
Rolex allowed some prisoners of war to order watches and defer payment until after the war. Antiquorum’s 2007 Nutting lot lists a receipt dated 8 July 1943, an order acknowledgement, a dispatch note, a guarantee and correspondence with Hans Wilsdorf. The catalogue says the watch was “sold gratis”; a 1948 letter in the archive gives the balance as £15 12s 6d.
Nutting was a Royal Corps of Signals corporal held at Stalag Luft III. The catalogue records that he ordered the watch in March 1943 and kept papers and photographs from the camp. The watch is associated with the Great Escape because it was at the camp before the March 1944 breakout; no cited document shows that Nutting used its chronograph to time the escape. The archived catalogue gives an estimate of CHF 130,000–160,000 and shows no hammer price; the often-circulated £66,000 result is unsupported by that record.
Antiquorum’s 2023 catalogue documents a second example, case 185985, delivered to USAAF first lieutenant Leon W. Brownlee, who was held at Stalag VII-A. Phillips has published a separate account of RAF officer Douglas S. Dickins and a 3525. These are individual provenance records; they do not establish the number of watches Rolex sent to camps or a complete “POW” production variant.
Serial numbers and dating
Sotheby’s 2020 catalogue divides its examples into two case-marking groups: an earlier series with reference and serial on the outside of the caseback, and a later series with the reference inside and the serial between the lugs. It dates those groups broadly to 1939–42 and 1942–46. These are auction-house dating conventions. A serial number alone does not establish when a watch was made or delivered; compare the markings and original paperwork on the specific example. See the serial-number guide.
Auction record
Selected catalogue entries. Estimates are not results; where a public result is unavailable, it is stated as such.
Estimate CHF 60,000–100,000; result not recorded here
This is a small, selected set of catalogue records, not a census or a current price guide. Auction descriptions and dating are attributed to the sale house.
Steel 3525, front view
Dial and case profile