stratsandaks-
Brother in law has a .223 MAK he keeps for a friend in his safe. Its got a threded muzzle, and a butthole stock. There are one of two 'options' on its legality-
1. It contains some American parts. If you replaced your FC parts with American stuff, but retained a thumbhole stock, you could have a Bayonet lug OR a threaded muzzle, OR etc...
2. The weapon was made before the 1992 ban, thumbhole stocks, although more rare, were Daddy Bush's ban, not Klinton. If the rifle is post-89, but pre-92, it's probably still OK.
Personaly? Who needs a bayonet lug or a detachable flash-hider? Having a few pre-ban guns with screw-on flash/muzzle devices, I never take them off, and they work probably as well as if they were welded/pinned on....As for the bayonet thing...hell man, an M-4 is WAAAY too short to be bayonet fighting with, I'm breaking out the 98/22 Mauser with the WWI "Butcher Blade" saw-back bayonet. Gawdamned thing is a PIKE with that blade on it...