Zenith tank watch approx 1939 £500

Bought this a year or so ago, but looking to concentrate collection. Keeps time fine, and I believe was serviced in the last 5 yrs but don’t know how long things this old go between services. Dial is nicer than most I see. Case has what I think are idiot opening scratches on side and normal wear and tear w age. Size about 24mm wide by 34mm. Hirsch branded strap and buckle included

UK postage free royal mail others to be agreed. First thing I have sold here so no feedback.

A couple more pictures to show back and case