Came across a German air pistol with some unusual markings stamped on the butt of the pistol. They appear to be "lb/sl". The air pistol was made between 1927-1930 and the "1586" is the serial number for the air pistol. I have come across over 700 examples of these air pistols but I don't recall seeing this stamping on any of the pistols. There is also the number "948" stamped in the wooden grip. Someone said they thought these might be German Police markings with 948 being the inventory number. Any insight or information that you could provide would be greatly appreciated. Thank you in advance for your time.