unknown hunting weapon

Comes from a collection and has been shortened or modified for hunting.
Fore-end made of bone. Total length approx. 92 cm.
Condition see photos.
Without proof, therefore only as a collector's weapon.
Other:

This item is a private sale. No commercial background.
Warranty, guarantee, or returns are excluded.
The sale is made under exclusion of any liability for material defects.
Air rifles manufactured in the Federal Republic of Germany before 01.01.1970 and in the former GDR before 02.04.1991
that do not bear an F mark are still freely sellable from the age of 18.