Roland Young wears an unidentified watch

René Clair's 1945 adaptation of Agatha Christie ditched the novel's ending — everyone dies in the book — and let two characters survive, following the stage version Christie had already written. The lighter approach made it a hit. Roland Young plays William Blore, the retired Scotland Yard inspector who shows up on Indian Island pretending to be a South African gold magnate named Mr. Davis.

Blore wears a rectangular-cased wristwatch on a dark leather strap. It switches from his right wrist to his left between scenes, a continuity slip that's easy to catch if you're watching for it. The rectangular case is period-correct for the 1940s, when tank-style and rectangular watches were standard men's dress pieces produced by companies like Bulova, Gruen, and Elgin. The specific make hasn't been identified.