amanico[JLC Moderator]
400052
An old Mathey Tissot Chronograph.
Long gone, but not forgotten, and in a splendid house.
38 mm steel case, radium dial and hands. From the late 40's, early 50's.

Screw in case back:

Good old Valjoux movement.
These vintage Chronos are just awesome.
Best,
Nicolas