1940s Welsbro rare Landeron-42 chronograph Black gilt dial with 3piece water-resistant case

This is a rare 1940s "Welsbro" chronograph featuring a Landeron 42 movement in a 37mm stainless steel 3-piece waterproof case. The watch includes a black gilt dial. The highly rare 3-piece waterproof case, comprising the bezel, middle case, and case back, represents a transitional period in waterproof chronograph manufacturing. The movement is the rare Landeron Cal. 42, a modification of the high-end Cal. 39 to a 3-register design. The dial, crafted using the gilt method, features a multi-color and scale design with a silver tachymeter and a brown telemeter, exuding the compactness unique to 3-register chronographs and the solidity typical of early waterproof cases. While Longines also produced 3-piece waterproof chronographs during the same era, their production was short-lived, making them extremely rare on the market.