

Spot on. Anything based on the AR-18 design, which begat the AR-180 semi auto civilian version (which was promptly banned), gets rid of the buffer tube function on the AR-15 to balance the BCG. It uses the dual captive recoil springs, a design that migrated to a bunch of other modern firearms.
I’ve been interested in the Aly & Kaufman AKB-23, basically a L85/SA80 replica lower that you throw a BRN-180 on and add some furniture to complete the look. So short version, yeah I think you could whittle a wooden lower for AR-18 style uppers. Probably only get a few shots off before it cracked though, wood can be quite brittle like that.










Wait 'til you hear who invented it…
That said, considering how many illegal services continue to run on it, I don’t think it’s as porous as some make it out. Definitely has well-documented weaknesses but the project maintainers tend to address them fairly straightforward.
Of course, you’re also just as likely to be buying drugs off an Onion market that the FBI seized and kept running just to catch more bad guys, despite it also hosting illegal content itself.