I would be surprised at a matching mag for a postwar P38. Otherwise, without pictures it would be hard to give a good estimate, 400-600 maybe as a good shooter. Many factors such as who used it before, import markings or no, reworked with heavy slide/hex pin or not, etc. all come into play. Pics!
the date and serial numbers on the mag are the same as all the ones on the gun. Id say he was desperate or maybe I got lucky. Its 57 years old, I’m 66, I can’t see any overstep marks, I’ll take the luck and leave it at that. It makes a better story
If it’s dated 61 it’s a p1. I bought one that was sold as a p38 with double zeros to start my serial # which means it’s a Russian post war gun but lower receiver is aluminum and has a date of 10/59 which makes it a refurbed to a P1. Same exact gun but redistributed. The value on even a poor P38/P1 is around 600.00. A good from ww2 or just after the war can run up to 1500.00. Great fun to have. I actually carry mine. I’d you can find a used Ruger P89 holster they fit perfect for a belt carry.