Classic and elegant, 10K Gold-filled. Needs cleaning.
The watch is about 31 mm diameter minus the winder, small by current standards but common during WW2 and common post-WW2 for some brands especially Mido (who are still going as part of the Swatch collective with Omega, Tissot, Longines etc). There is no serial number on the exterior of the back but it may well be on the internal surface.The movement is 17-jewel because the only alternative is a 39-jewel version which would have its exalted status printed on the dial. The style and size suggest that this watch is a first generation "Gyromatic" with a G-P calibre 47 movement, a modified ETA calibre 1256, the first fully circular rotor excursion movement made by ETA. It may be a simple movement but some people rave over the finishing on this and its date included sister, the 1258. If you had unwound the back in order to display the movement, the G-P enthusiasts would have been able to see enough with the rotor moved between two separate photographic angles to pick the calibre.