Found this wristwatch in the deep Russian provence. Landeron 51 calibre inside:
manual-wind chronograph, 60s, 30/45min, cam switched
13.75''', Dm= 31.0mm, Do= 31.5mm
f = 18000 A/h
power reserve 42h
Timepiece in good condition, only hands and glass must be replace. Will do it after winter in warm countries :)
Good accuracy, gold plated without scratches, but need a polish, sure.
And it is beautiful model for photosession :)