I have a 1939 Mauser with all matching numbers, except for the magazine. Finish is about 90%. It also came with a WWI black leather holster and an extra magazine. I have shot it some since I bought it some 25 years ago, but not a lot. I have also never had any problems with FTF or FTE with any of the ammo I have used over the years. The only thing I have encountered is that sometimes on the last shot, the toggle does not stay open because of the less powerful ammo.

I would agree with robertrwalsh that the 1920 commercial models might be the most inexpensive Lugers around. They don't have all the markings of WWI or 1930s WWII Lugers, but they do work just fine and can be a good starting point.

Good luck!