[HerrKaiser]

Not sure about actual date made, but the early postwar commercial lugers had 5 digit serial numbers at first IIRC (I have one of the 5 digit ones) and those were made in 1919-20 and into early 1921. After awhile they switched back to the military style lettering like yours, these commercials are sometimes referred to as “Alphabet Lugers”. Unfortunately, since the alphabet lettering block reset every year, it’s difficult to discern when yours would have been made. Could have been any year from 1921-30/1 when the DWM inventory was finally exhausted and it was absorbed into Mauser.