First Luger: 1921 DWM

[boyscout775]

This is my first Luger that I just received a few days ago. It is a WW2 bring-back off of an officer in late 1944 in northern Italy. It hasn't been messed with since it was brought back. It appears to be all-matching except for the magazine. The rifling is good with only minor frosting, and is dead acccurate at 15 yards with 8 rounds in 1 1/2". I would like to know any information I can on it, including a price range. It has a lot of 1's stamped all over it. I believe the unit mark means 2nd company 18th infantry regiment weapon 42. I would like to know some additional information on that if possible. I get lost when the Weimar units changed to Nazi units. Would the pistol have stayed with the same soldier through its entire service? Thanks for any help, and if I need to add more pictures just let me know.