Can you post more pictures? You might also like to post on the .22 forum here at Gunboards. The rifle was probably sold as a commercial rifle to the youth group in Stuttgart. The serial indicates that it is an early version of the Gustloff KKW made soon after the change from BSW. Pix of the commercial proofs would be nice and might help date the rifle. For more info on the type, see Jon Speed's book on smallbore Mausers.