My latest project is an XM-607 Clone I'm building on a Palmetto lower.
The first AR I owned was in the mid 80's.....M16A1 20" upper on a Palmetto lower with an A1 butt......I never remember it giving me any problems.
I just picked up a "BH-15A1" Palmetto lower in the 4XXX ser. no range.......I really like the no-mag release-reinforcement look (slabside), the ability to use small-hole uppers without offset pins/ bushings, and ,to be honest, the Palmetto Armory logo! Apparently they were made '79-'82 (according to Oly Arms website). Every upper I've put on it seems to fit well (so far anyway). Definitely milled from bar-stock. I don't know what kind of anodizing they used, but both I've owned had a very light , almost greenish-grey finish........like that of a well-worn SP1. I just polished the finish off of my upper to match it.....kind of a "well used but not abused" look...........
I can try to get some pics of mine
As soon as Tom in WA is done with my barrel/handguards (wink wink) I'll post some finished product pics