Reference:2303

Pre-Daytona chronographs → 2303

Steel ref. 2303, case 021'188, Monaco Legend Auctions lot 223.

Ref. 2303 is a compact, manual-wind monopusher chronograph documented in auction records from the mid-1920s through the 1930s. Examples have round or tonneau-shaped cases, two-register dials and snap-on backs. The pusher usually sits in the crown, though one Christie’s example places it in the case band.

Core facts

Detail	What the records show
Type	Manual-wind, single-button chronograph
Dated examples	Auction estimates: c.1926–c.1936
Case	Stainless steel and gold examples; round and tonneau-shaped cases, 26–30 mm in the cited records
Movement	17-jewel lever movement; several Antiquorum catalogues give 10½ lignes. The lots name no caliber or maker.
Display	Two registers: running seconds and 30-minute chronograph counter
Caseback	Snap-on in the cited examples
Date / water resistance	No date; catalogues give no water-resistance rating

Where it sits in the line

The 2303 belongs to Rolex’s early non-Oyster chronographs, before the later Oyster cases and the Valjoux 23-based Cal. 13 group covered in the pre-Daytona chronograph guide. Christie’s describes its launch as mid-1920s. The surviving records show a monopusher design in several small case forms; the later Cal. 13 chronographs form a separately documented group.

Production outline

Auction catalogues date individual watches from circa 1926 through 1936. Antiquorum dates an 18 ct gold example to circa 1926. Christie’s dates steel case 021187 and case 022310 to circa 1928, and an 18K gold Broudarge Paris example to circa 1930. Other catalogues date examples to 1935 or 1936; these lot estimates do not set factory boundaries.

The catalogues give conflicting dates for case 021187: Christie’s says circa 1928; Antiquorum says the 1930s.

Movement notes

The catalogues describe manually wound, 17-jewel lever movements. Antiquorum gives 10½ lignes for several examples; Christie’s describes nickel-finished movements but often omits the size. The ligne figure is a movement-size measurement. Antiquorum entries also report monometallic balances and Breguet balance springs on individual watches.

The dials have subsidiary seconds and a 30-minute chronograph counter.

Dial map

A two-tone silvered sector dial appears in steel and gold examples, with variations in numeral style and scale. Documented examples include Arabic numerals, Breguet numerals, baton markers, and combined Arabic-and-baton layouts. Tachymeter scales are common in the sample; Antiquorum also records a 30-pulsation pulsometer dial, while a separate 18K gold example has a black dial.

Retailer signatures appear on examples catalogued for Broudarge Paris, Gobbi Milano, Ronchi Milano and Kirby. Christie’s also describes one watch signed by R.W.C. Ltd.

Dial close-up of case 021'188; the bracelet crosses the left register, Monaco Legend Auctions lot 223.

Case, bezel, crystal, and crown notes

The cited cases measure 26–30 mm; 28 mm appears most often. Antiquorum’s 1990 listing calls the watch “Tank”; its photograph shows a round 26 mm steel case. Christie’s describes round and tonneau-shaped examples; its case 022310 has downturned lugs. Auction records identify stainless steel, 9K gold and 18K gold cases. Christie’s also says the model was available in 14K gold.

Snap-on backs appear in the catalogue descriptions. Several examples have a crown-coaxial pusher; Christie’s case 022310 has its button in the case band. The catalogues give no dated sequence for those arrangements. Crystal material and water resistance are unspecified in the records reviewed.

Caseback of case 021'188, Monaco Legend Auctions lot 223.

Bracelets, end links, clasps, and packaging notes

Monaco Legend lists case 021'188 on a stainless-steel Gay Frères bracelet, approximately 180 mm long, without describing its delivery history. Other records describe leather straps and Rolex buckles: Antiquorum lists a gold buckle with case 17890, while Christie’s notes an 18K Rolex buckle stamped SAR with case 17'887. Each is a lot-specific association.

Historical market and auction record

Sale	Example	Recorded result
Antiquorum, Geneva, 14 October 1990, lot 144	Steel, 26 mm, pulsometer dial	CHF 32,200
Antiquorum, Milan, 25 March 1996, lot 95	Steel, case 021187; 28 mm	ITL 12,653,500
Antiquorum, Geneva, 14 May 2006, lot 137	18K gold, case 17890, retailed by Ronchi Milano	CHF 88,500
Monaco Legend Auctions, 25–26 April 2026, lot 223	Steel, case 021'188, Gay Frères bracelet	€175,000 including buyer’s premium

Monaco Legend notes that case 021'188 appeared earlier at Bonhams in 2014; the two entries concern the same watch.

Gallery

• 
  Full watch, case 021'188
• 
  Angled view, case 021'188
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  Dial detail, case 021'188
• 
  Caseback, case 021'188

Sources

• Antiquorum, "Antiquorum Hong Kong — Rolex ref. 2303, lot 87", Antiquorum
• Antiquorum, "Antiquorum Geneva — Rolex “Tank”, ref. 2303, lot 144", Antiquorum, 1990-10-14
• Christie’s, "Christie’s — Rolex ref. 2303, case 021187, lot 5674766", Christie’s
• Antiquorum, "Antiquorum Milan — Rolex ref. 2303, case 021187, lot 95", Antiquorum
• Christie’s, "Christie’s — Rolex ref. 2303, case 022310, lot 4796029", Christie’s
• Christie’s, "Christie’s — Rolex ref. 2303, case 17'887, lot 5130737", Christie’s
• Christie’s, "Christie’s — Rolex Chronographe ref. 2303, case 16'728, lot 5690990", Christie’s
• Christie’s, "Christie’s — Rolex ref. 2303, signed R.W.C. Ltd., lot 1599679", Christie’s
• Christie’s, "Christie’s — Rolex ref. 2303, case 14743, lot 4272133", Christie’s
• Antiquorum, "Antiquorum Geneva — Rolex for Gobbi Milano, ref. 2303, lot 175", Antiquorum
• Antiquorum, "Antiquorum Geneva — Rolex Antimagnetic ref. 2303, lot 515", Antiquorum
• Antiquorum, "Antiquorum Geneva — Rolex ref. 2303, case 17890, Ronchi Milano, lot 137", Antiquorum
• Antiquorum, "Antiquorum Geneva — Rolex ref. 2303, case 16121, Kirby retailer, lot 491", Antiquorum
• Monaco Legend Auctions, "Monaco Legend Auctions — Rolex ref. 2303, case 021'188, lot 223", Monaco Legend Auctions