Since I learned something and most people might already know it I wanted to toss it up in this thread. Below is a reference for rear underfolder trunnion's.
My stock assy. was correctly ID's as a Yugo and not Polish. That tip alone saved me from ordering the wrong receiver. I will go with a NDS-M92 once I line up a local FFL to receive it in for me.
Below is a pic of three rear trunnion's for comparison:
Note the difference between the Polish and Yugo rear trunnion's angle of the back edge. The Polish back edge is 90 degrees to the top rails, while the Yugo back edge is more than 90 degrees as it angles forward from top to bottom.
My trunnion has an "extra" hole that should make it a Yugo M70 trunnion~
Note hole that breaks thru the top~
Since my rifle will be Polish & Yugo maybe its correct name is now a Pugo ?