The present ref. 6239 features a number of traits that classifies its rarity such as the “Double Swiss” designation at 6 o’ clock. Partly visible and mostly hidden by the case within the production batch, the present example bears a serial number of 923’378, just 2 number away from a similar example that was sold in Phillips Geneva Watch Auction XVIII with case serial 923’375.

The double Swiss designation is a rectification done by Rolex as the first Swiss is mostly covered by the case when the dial is mounted, thus prompting the company to add an additional clearly visible “Swiss” designation. The bezel also represents the earliest MK1 iteration with 275 designation and small hashmarks all around. Powered by the calibre 72B that was used during the early part of production, the specimen has ages with a warm layer of patina throughout the dial. Taking a closer look under the loupe, engraved numbers, potentially for inventory purpose, can be spotted behind the lugs.

Acquiring such a piece not only represents a connection to horological evolution of chronographs, but also an incredibly rare find produced during the first year of the ref. 6239.