I've RIA drawings specifing barrel markings on a completely new USGI rifle and that marking is not authorized. Yes, I'm positive the higher receiver is Colt, combined with the BCG. It is really the barrel that may be questionable to me. Thanks so much for chiming in with the details https://coltm16a1forsale68900.ttblogs.com/10790950/the-greatest-guide-to-colt-m16a1-for-sale