To have the exact same feed issue with -six- different magazines sure makes a case that the pistol is causing the issue. Recoil spring is certainly the easiest thing to try, and the next thing to look at would have to be extractor, as a properly working extractor obviously must pull cases from the chamber but perhaps not quite as obvious -- a 100% functioning extractor is a huge part of the feed cycle of any semiauto pistol.

I do have hands-on experience in dealing with a 52-2 extractor, sorry that I don't have advice for the earlier and scarce 52-1 extractor.

But no panic -- it sure seems to run fine for the rest of the ammo in the mag, so maybe a new recoil spring is all the medicine needed.

Oh, and yes, I believe you are absolutely fine to use a recoil spring designated for a 52-2 in a 52/52-1.

Please keep the updates coming and good luck!