OK, Colt called back, you guys are correct, the collet bushing went on all 70 and 80 series guns except Officer, Commander and Defender models. So I guess the collet was standard on all full size series 70 and 80 Colt 1911s.
I bought my Series 70 Gold Cup new, and it had the collet bushing. The other two Series 70 45s I bought used, and they didn't have the collet bushings, so some one must have switched them out. (I switched out the one on my Gold Cup a while back too). I also have 9mm Series 70 Combat Commander that came with a standard bushing.