ydduit,
The drilling seems to have been proofed in Zella-Mehlis in June(if that is a 6 next to the 05)of 1905.The 1079(?)is the ledger number.The 108.49 is the bore dia, expressed in ga.measurement. This is one of the marks found on 9.3x72R,but may also be found on other calibers as well(9.3x57R comes to mind). The way to be sure is to make a chamber cast.If this is not possible,percentages would be on the side of it being 9.3x72R.As long as the barrel is in good enough shape,ammo for any of the 9.3s can be loaded(factory ammo for x72R is avaliable).The shotgun barrels are"short chambered" with 2 9/16"(65mm)chambers and both are choked(usually pretty tight).The groove dia.of rifle barrels with the 108.49 marking are usually around .362-.364". You are correct that the selector/safety arrangements are a little unusual on drillings of this type/age. Maybe Axel or Raimey can shed more light on this.You might say the gun was made in eastern Germany,but in 1905 there was no East Germany.I hope you find this helpful.
Mike
