here are left and right side views of the modded receiver:
looking at the finished receiver from the left rear quarter:
and another view from the right front quarter:
still unpainted, the receiver now has the proper mag dimples, reinforcement plates, and rivets. the receiver cover has the proper cut allowing for proper fit with the rear reinforcement plates, the bolt carrier has the right indent cut:
and the proper barrel pin block:

the barrel block still lacks the holes for the pin -- still trying to see how a pin (or maybe a small bolt) can be anchored on the block to add to overall structural rigidity.