"Last I heard they wouldn't letter from Colt. Colt put out a disclaimer saying they didn't build them and wouldn't warranty them and I've heard several people say they tried to get them lettered and Colt won't letter them. Colt only licensed the 3rd gens and had no part in the building. Colt at least did the final fitting and finish on the 2nd gens."
Actually I did get some 3rd Gens lettered by Colt, so it was done in some instances early in the series release by Colt Blackpowder Inc.