looks to possible be naval markings. I have no Imperial books but, wait for others to chime in. O is for Ost. fleet. Barrel marking is possibly the same.
Definitely served with the Navy at some point. I believe that the grip strap markings are more consistent with Weimar or even NS era service. The other markings certainly look period, but I've never seen them before. Is the magazine matching?
From the E/O inspections on all the pressure bearing parts, it looks like it cycled through a Navy Depot, probably Kiel, for repairs at some point, but its hard to tell what was done from these photos.
Definitely served with the Navy at some point. I believe that the grip strap markings are more consistent with Weimar or even NS era service. The other markings certainly look period, but I've never seen them before. Is the magazine matching?
