I built this one up from a stripped Colts lower (one of their competition lowers).
It's not period perfect and doesn't have one of the 1:14 or 1:12 twist barrels.
I wanted a 1:7 chrome lined FN barrel and it has a flat top upper with a detachable carryhandle because there's no reason to go all the way backwards.
It does have a teardrop forward assist, 3 prong flash hider, A2 stock, old style bayonet, Colt bolt group, tubbs flat coil chrome silicone buffer spring and set of old handguards.
I really enjoy shooting it. It's one of the nicest shooting AR's that I have, and there are many.