One of those projects I picked up that never went anywhere. Since it has the rebated front lug for the early 601 front pin (I guess Colt kept that feature until pretty late in production for interchangeability) it is a Colt; none of the commercial-made A1's I've ever seen have had that. No forge code, looks like a square XM16E1 forging, but I honestly can't tell the difference between those so for safety I'll just assume it is a round forging, which would be 1968-70 according to Ekie. Proofs were lost in a refinish somewhere. Finish looks to be some kind of back on spray, but it is very well done and is very close to Colt gray.
SPF Asking $85 shipped. First 'I'll Take It' posted gets it, just send me a PM after.