do what you feel comfortable with, but NO ONE cares about 922r expect a few internet people. Back when I worked in a gun shop 15 years ago, you wanna know how many "922r compliant" used guns came through here? probably about 25% or less. Most people took WASRs Mak90s and what not and slapped surplus furniture on them and didn't give two craps about it. Being that no one in our shop "assembled" that gun, 922r wasn't even a thought in our minds and shouldn't be on yours as a buyer either.
Not to mention do you think anyone can AUTOMATICALLY assume your rifle is 922r non compliant? The cops don't even care about it (seriously, my whole family are cops, no one even knows what 922r IS) and if they DID start sniffing, how would they CONFIRM that your parts aren't 922r compliant? There are hundreds, if not thousands of manufactured parts in the US that don't have some "hey I'm 922r compliant!" banner across them. Which means they would need to strip down your rifle to the last part, run a metallurgical analysis on the parts and then try to prove in a court of law that you assembled (built, not just slapped in a mag or swapped out a pistol grip) the rifle in that configuration with non compliant parts. yeah, that's happening (/sarcasm) and no cop or ATF agent is just going to start sniffing at your guns and do that. But as I said, do what makes you feel comfortable. But again, that's all hypothetical, as the big question is... did you assemble (build) that gun? if not. it doesn't matter to begin with
if this super duper ruffles your ridges, then just grab a $20 cheapo Rak-1 trigger and swap out the FCG... now you can put a real yugo grip on there if you want to too and sell the Yugo FCG on "the files". People would snap up a brand new com-bloc yugo FCG in a second and you'd make most of your money back. *shrug.