Possibly an Imperial dagger with an updated pommel and scabbard.
Searching for anything relating to, Anton Boos, 934 Stamm. Kp. Pz. Erz. Abt. 7, 3 Kompanie, Panzer-Regiment 2, 16th Panzer-Division (My father)
Many thanks Ralph
Most probably updated with the Nazi pommel added. I do not think from Imperial, more probably Weimar. The scabard decoration and bands are attractive. The markings show it to be an issue piece, not private purchase. The "O" signifies Ost for the Baltic fleet. An "N" seen on these earlier dirks signifies Nord, for issue by the North Sea fleet.
Here are some pictures of a standard issue dirk from the Third Reich period. I believe that the Hamburg markings denote it as issue from one of the Naval training establishments.
nice post 2 nice daggers.
The model that is shown by Luca is a 1929 model navy dagger with the 1938 replacement eagle. The markings on the blade are socalled "depot markings". A very nice dagger.