Hi Quinn, Welcome!!
1934 to early 1939 are S/42, then to early 1941 they are code 42, then to 1942 they are byf. The metalurgy in these Lugers is superior to the early pistols, so they are the strongest shooters. I would say any, but the later pistols are more reasonable, if any nice Luger is reasonable!!!

I think you hit the nail on the head with a 1940 to 1942 choice!! Good Luck!