I just picked up 2 Colt BCGs from Brownells last week. You have to check their website every day, sometimes 3 to 4 X a day lol. They have C markings on the carrier and the bolt has a white dot and MPC so they look legit. In a sealed white bag marked Colt.
Good thing about Brownells is they have the best return policy ever if you dont like what you get, even years later lol.