SN is 10343.
A37 is not the sn, speed shows an barrel that is also stamped A37 with an complete other sn.

Another interesting thing is that the barrel is signed "Marholdt Peterlongo Innsbruck".
I think the engraving was also done by Peterlongo.

The gun was in use by an hunter, but there is no info since when. It comes up after he died.