vblue42: Thanks.
Neither thickness was a concern. The ZPAP is my fifth imported AKM. Have frequently read AKfiles for ten years (watched AKOU 5,000-rd. evals, recently).
I knew years ago (am age 66) which guns are stamped and milled.
Obviously ZPAP has a pretty strong receiver, having been designed to shoot (formerly) "Yugo" or Serbian grenades---