If the stock and upper handguard are American made , like a Choate, you would have to replace 3 more parts; if you also replace the magazine with something like a Tapco, then you just need 1 more part; the magazine body and the follower each count as a separate part.....
So with a USA stock, handguard, and mag, you would need to replace 1 part on your Yugo to be compliant; you can replace the sear or the gas piston and be done.