1940s steel tonneau vintage Longines ‘Asprey’ watch

A steel tonneau vintage Longines watch, retailed by Asprey. The case measures 21 x 31.5 mm (excluding lugs). The case is marked Acier Inox Staybrite and numbered 20 2239. The movement is signed Longines, Swiss Made with seventeen jewels and numbered 5669446. The silvered dial has black Arabic numerals with a subsidiary seconds dial. The dial is signed Asprey above the centre with Longines above the seconds dial.