1930s Longines Cal.25.17 rare Tonneau design with Black gilt dial in Staybrite

This is a rare late-1930s Longines tonneau-shaped model powered by the Cal. 25.17, featuring a black gilt dial.

At first glance, the round dial set within a tonneau-shaped case gives the impression of a watch housing a round movement; however, this unique piece is fitted with Longines’ in-house rectangular movement, the Cal. 25.17. The dial is an uncommon black gilt type for this period, and the presence of the “Anti-magnetique” designation—rarely seen on time-only models—further enhances the watch’s rarity.

Despite its compact size, the watch is thoughtfully engineered with practicality in mind, featuring a double-structure case with a dust cover, the anti-magnetic Cal. 25.17 movement, and a black gilt dial with luminous material.