922r does apply to rifles built in the US and does apply to guns using a US receiver.
Sorry for the confusion, I misread what I quoted. The receivers (from both builders) are American (as well as the barrels), but 922R DOES apply to US rifles using foreign parts (made after 922r enactment - a bane of my existence).
Now the two I have in front of me (a grey park finish HEB and a black park finish HEB - my glossy SW is in storage), are like yours - converted Malay FA trigger packs with the C hammer/sear and cheap trigger. I have the cheap (likely US made) poorly painted checkered grip trigger housings. Charging handle on the grey park is market with a C on the underside at the base so I'm assuming its also a US part if the Hammer/Sear are, this leaves the trunion and flash hider as the wildcards.
The only place where 922(r)(2) gets murky is if you make a Form 1 SBR and under section 4(i) put "testing/experimentation"....but I digress its cheaper to stay in compliance then to defend yourself in court.
An RCM bolt carrier or US made trigger pack is what I plan to swap so I can use nicer German C/P grips when I have a few extra bucks.