I have a Century built Polish underfolder AKMS and was wondering if I could add a bakelite grip. I know the trigger group is USA built but I am not sure about the barrel or receiver. Was hoping you guys would know for sure.

Barrel and receiver are US

That is enough compliant parts to add the bakelite grip correct?

From the factory I'd bet that the US Parts are:

Receiver
Barrel
Trigger Group (3)
Pistol Grip.
Muzzle device (Not necessary, so maybe, double check)

You might have to put a U.S. made muzzle device if there isn't one already one on it. If your muzzle device has a "C" on it or is otherwise marked that it is made in the US, you should be okay to just swap pistol grips. If not, get one from Tapco for $10 and put it on and then switch to a bakelite grip.

Slant brake has a C on it. Looks like I'm good to go. Thanks