This is a military Luger, not a commercial one. Only millitary lugers had the four digit serial number with a letter suffix; commercial ones had the complete serial number. The acceptance stamps are military. The military marking of the year of manufacture on the receiver ring over the chamber hasbbeen ground off, probably after WW I. In the picture of the pistol from the front, note that the thickness of the receiver around the barrel is much greater on the sides than on the top.