I figure the kits were purchased from SARCO, and you can get them cheaper there (cut out the middle man). Last I knew you could buy the surplus parts from SARCO less all the aftermarket stuff for a much better deal.
These are US Air Force M16 (Colt's Model 604) barreled uppers with handguards, buttstock and screw, grip, and fire control groups removed from old rifles updated with an M16A2 conversion kit. You are looking at about $250 in parts, along with a bunch of junk stuff, like the cheapest bolt group, charging handle, receiver extension, etc parts that they could find to round it out, or as they say "a few smaller ones are careful reproductions". Not sure that fire control group is original in the kit pictured, could be junk, or could be real parts that are neutered.
The barreled upper in the sample picture dates from 1964-67. Barrels from this time frame do not have a chrome chamber, all my non chrome barrels from 64-67 work fine, but others have had real bad experiances such as this:
www.jouster.com/articles30m1/index.htmlIf not a former rebuild the upper would be gray, and current production lowers are black.