1920 Single date

According to Still, Weimar Lugers, The MA marking stands for "Marine Arsenal" I believe or "Marine Artillerie" I have seen it defined both ways...at any rate it was re-worked/conditioned by a Navy arsenal. In other references one can find some discussion of the German Navy's Artillerie Arsenal performing all manner of equipment conversion and even manufacture ie Luger holsters. This marking has much earlier been attributed to mean "Mauser Arbieten" or Mauser Worked/ ie reworked. I agree with Still's explanation. All of these pistols that I have seen are property marked with the O for Ostsee and tend to show a good bit of wear and use, with many showing mismatched parts....which I feel happened while in German service. I do agree that you should check the serial number suffix, I believe that most were "S" block..but I am not positive. They seem to have been produced around 1929? and the 1920 date you see is merely a Weimar property stamp and not a manufacture date. IMO these pistols are fairly rare and desirable.