1938 S/42 refinished shooter

[ithacaartist]

Yep, it's an aftermarket. The spot welds and double, rolled pins to hold the bottom are the tells. Original or good quality mags are folded and staked at the top. The shape of the latter will vary with manufacturer. Original mags up until the end of WWII have a single, solid retaining pin.

FXO mags from the end of the war are forged and machined, with aluminum or Bakelite bottoms that are retained very differently.