New S/42 in the family tonight

[rivieraranch]

I have owned some Luger pistols in the past; the last one was about 20 years ago. I recently began looking for a Mauser Parabellum. Naturally a search like this leads to other things. Tonight I wandered in to a neighborhood gun shop a half an hour before closing. My wife and daughter were with me. I saw this Luger lying in the bottom of the cabinet with some other used stuff. I could see that it was mirror refinished and re-strawed. I asked to look at it. It looked nice enough and the price was very reasonable on it; much to my family's dismay I said, "I'll take it."

It is a 41 S/42 with a 4-digit serial number. I have not disassembled it but the numbers I have seen thus far match. Obviously the clip and grips are reproductions. I am buying it to shoot.

The restorer did an excellent job. The corners of the metal are not rounded. The Nazi proofs were completely removed from the right side of the receiver. That is fine with me. The restorer also chose to straw the trigger, take down lever, safety catch. magazine catch, ejector and also the extractor. It is not how a 41 S/42 would have looked originally, but I prefer straw for the small parts.

The only question I have is regarding the small proof mark below the take down lever. What is that?