Hallo,
here is the internet adress of the Hohner Museum in Trossingen, where you can see a lot of Hohners out of the old days
(they show you the rooms with artefacts).
Best thing however would be, you join the Hohner workshops in Trossingen comming in November and visit the museum yourself!
The one you have and show here, looks like a “war” harmonica, leaned on a pistol cartrigde.
Greetings
Kerstin