Tony, Tom Heller provided some very solid advice. Lots of others should also heed it. I can't tell you how many guns that I have purchased and that were grimy, dirty and a little rusty inside from neglect. A little elbow grease and oil is an easy prevention to that problem - along the way, as a part of responsible ownership (stewardship).
thanks
Jack

Yes that is why I bought this one. I didn't see serious pitting and it looked to me as well it would clean up real nice. We can't all buy perfect condition guns and I was looking for a bit of a project. The first thing I always do is disassemble and clean and scrub and oil. That is the fun of it for me. I like the mechanics of how guns go together and get them in perfect working condition. Working on them is almost more fun than shooting them. Well, not really. I shoot what I collect and I only collect what I can shoot.
This one will be my oldest gun yet.

This Luger is shootable, that's an advantage. If some small parts break in shooting, then, need to find replacement parts, then, starts another cycle of searching on market. In this process, lots of fun. Also, would find the strong and weak points of the gun, understand it from user's angle. That's great experience IMO.