Was this an assembled MAK that was demilled? Does it have the front trunnion? Most MAK kits didn't have trunnions and they are almost impossible to get. I built two from kits and bought two of the last three Chinese trunnions from Global Trades back in 2006.
The Chinese used a thicker receiver than most others. So the trunnions are going to be slightly narrower. IIRC, the difference was 1mm vs. 1.5 on the Chinese.
Haven't been keeping up with who makes receivers in that thickness. Armory used to. Elk River Tool and Die makes a 1.6mm. Other than flats or blanks, Firing Line makes milled chinese type receivers.
922r compliance can be had with receiver, FCG (3 parts), gas piston, muzzle device or furniture. Ironwood Desgns makes Chinese pattern furniture for compliance.
Links that may help:
Elk River
Ironwood Designs