If you've got a WASR, word on the street says that the compliance parts consist of a Century made gas piston(1), Century trigger group(3 parts), and a Century gas piston(1). My WASR came with a G2 trigger, so I'd double check what you actually have. The Century trigger group and pistol grip are usually marked with a "C." And if yours came with a threaded muzzle brake, that should be Century too.
Of course this has to do with wood stocked WASR's, and black Century furniture might have been an alternative to them switching out gas pistons. You have to check what you have.
If you swapped your US pistol grip for a Romanian, you need to find another foreign part off the list to swap with a US part. Other than a US receiver, I'm not aware of any US parts that you don't already have. You may have to go back wiith the Century pistol grip.