1930s steel rectangular vintage Omega watch

A rare large steel rectangular vintage Omega wristwatch.
The case measures 22 x 39 mm (including lugs). The case is signed Omega, Fab-Suisse, Acier Staybrite and numbered 9903118 to the inside. The T-17 movement is signed Omega and has a protective cover. The two-tone dial has black Roman numerals with a subsidiary seconds dial and blued steel hands. The dial is signed Omega above the centre and fitted with a brown ostrich skin strap.