WWYS,
I believe that the frame of the Old Armory Original guns are also a bit oversized when compared to Colt and that the only difference between them and the standard models was that the cylinder window size and the cylinder were smaller. Gary Granger made reference to this some time ago on this board and stated that he would often try to talk people out of ordering the OAO models, which were several hundred dollars more than the standard models, because there was no difference, apart from cylinder size, between the OAO and the standard models.
CJF