1940s Cartier "Obus"with Rare EWC Movement Cal.409 Backwind in Rectangular Platinum Case

Manufactured in 1940s, a Cartier "Obu" model with a backwind movement, rectangular case in platinum, and a very rare EWC (European watch clock)?movement Cal.409. It is a very precious piece in the vintage Cartier collection, as it is made of platinum, which is a rare material in Cartier, where yellow gold is usually seen. Despite its small size, the rectangular case, with its distinctive Obu (cannonball) lugs, from which the model takes its name, and the weight of the platinum case give this watch a presence that transcends its size. Includes with its original 18 carat white gold deployment clasp and a non-original fixed leather strap with 16.5 cm circumference around the wrist.