Can anybody help me find any info on this upper. It is a true first gen upper and I was wondering if anybody knew who built it. Any assistance would be appreciated.

thank you
Matt

Check this site out.
[url]http://www.biggerhammer.net/ar15/uppers/[/url]

If it's marked C  M in the recess under the rear sight, it's a Colt upper.  Nearly all the A1 and all the SP1 uppers around are in fact Colt made.  There are, I suppose, some contractor built A1 uppers out there, since both Harrington&Richardson, and Hydra Matic Div. of GM made M16A1s, but I haven't personally seen any.

There a number of A1 uppers and barrelled uppers on the market recently; takeoffs from M16A1s that have been upgraded to A2 configuration. Under the Clinton administration they were apparently destroyed, but since Bush came in, they're just selling the take off upper assys in usable shape.[:D]