Rolex Chronograph 2507

The Rolex Chronograph reference 2507 is an exceedingly rare non-Oyster model from the late 1930s, representing a seldom-seen sibling to the more common reference 2508. Produced around 1937, its historical significance lies in its “oversized” case and its extreme rarity. The watch features a large 37.5mm three-body case with a snap-on back, making it one of the largest chronographs produced by any brand during that era. This reference is distinguished from the 2508 primarily by its scarcity, suggesting a very small, possibly experimental, production run. Known examples have been found in stainless steel and 18k yellow gold, featuring classic rectangular chronograph pushers. The dials are typically silvered or multi-toned, with complex layouts including tachymeter and telemeter scales. It is powered by a manually wound 13 or 14-ligne caliber, often the Valjoux 22. Due to its very limited numbers and large, elegant proportions, the 2507 is considered a “grail” for collectors seeking the rarest examples of Rolex’s pre-Daytona heritage.