I have a 30 rd Colt mag. It has 62667 on the right side and a dark green follower with what looks like 62665A in white on it. The floorplate is Colt AR-15 cal 5.56mm and the address. I know its early just don 't know if you consider it rare. If you are interested, make me an offer.
Almost forgot, I have some 20s too. Aluminum followers, Colt, but I don't think anything else is special about them.