Waffenampt real or bogus?

The carbine is off topic but the Waffenampt is not. Bought a Dutch Steyr 1900 carbine today. Has an Ha120 Waffenampt stamped behind the rear tang. It's a bit LARGE and DEEP. Carbine also has am told Dusseldorf police markings on the left buttstock. Think those are okay. Butt...what do you guys think of this stamp? Didn't pay a premium for the mark, little beauty is in fine shape and EVERYTHING is matching.

Thanks for any opinions,

Lancebear