Great watch just overhauled by watch guy who took loads of photos of the repair and restoration process. Follow this link after copying and pasting, https://watchguy.co.uk/cgi-bin/library?action=show_photos&wat_id=6892&tk_id=311442332

Christian, the owner of Watchguy, could not find a hand set spring anywhere as this tiny item needed replacing so has left it as it is. I am wearing the watch on a regular basis and it really is not a problem. Indeed, so confident I am in his workmanship that I am happy to give a 6month warranty on this lovely watch

Diameter without lugs or winding button is 33mm Approx.

A lovely watch probably dating from the 1950s.