Identification of USA parts?

[BlasterBob]

IF/when someone buys an imported semi auto rifle (of the ban era) that still has a butthole stock on it and he changes that stock to a pistol grip type, how does he determine if the required 922 parts that are needed to make the switch legal, are actually mfgd in the U.S.A. Are they always marked accordingly? This question may have been asked a gazillion times already but I don't recall ever seeing this particular question or a serious answer for it.
I know that I am probably opening the flood gates for a bunch of wise ass answers but I'd really like to have at least ONE serious answer - if that's even possible here - yeah, I know

[BPTactical]

Theoretically US components must bear markings denoting US manufacture.
Often a company name is sufficient, little of a grey area.
FWIW, not one individual has ever been prosecuted for 922r violation successfully. They have been nailed for other violations but not a stand alone case on 922r.
Homemade parts count as US manufacture as well.

[Ridge]

Thumbhole stock, not butthole

[Sharpienads]

Thumbhole stock, not butthole

Lol.

[TS12000]

Thumbhole stock, not butthole

I was debating if that was a typo or he just really really hates thumbhole stocks

[Ridge]

I was debating if that was a typo or he just really really hates thumbhole stocks

I'm still on the fence.

[mutt]

IF/when someone buys an imported semi auto rifle (of the ban era) that still has a butthole stock on it and he changes that stock to a pistol grip type, how does he determine if the required 922 parts that are needed to make the switch legal, are actually mfgd in the U.S.A. Are they always marked accordingly? This question may have been asked a gazillion times already but I don't recall ever seeing this particular question or a serious answer for it.
I know that I am probably opening the flood gates for a bunch of wise ass answers but I'd really like to have at least ONE serious answer - if that's even possible here - yeah, I know

To figure out how many/what parts to replace: http://gunwiki.net/Gunwiki/LegalFederal922rParts

US parts are generally marked with a company mark, like a 'C' in the case of Century or with 'US', like Arsenal does.

While no one has ever been prosecuted for just 922r issues that I know of, there's no reason to tempt fate. US parts are cheap compared to the cost of an extended stay at club fed. Don't give them a freebie to get you with.

[Rust_shackleford]

Is 922R a law or a made up ATF reg that never made it through a real legislative process? Funny how rules are made up by bureaucracies.

[mutt]

Is 922R a law or a made up ATF reg that never made it through a real legislative process? Funny how rules are made up by bureaucracies.

As far as I know it's an import law - Title 18 USC § 922(r). Although how the law is interpreted and applied is up to the whims of the ATF I imagine.

[Mtn.man]

I have seen a few Butthole stocks.