JDW that was what I was thinking also.I can't see any machining marks but that probably doesn't mean much. The gun smith gave me readings of .690rt and .700left. There is supposed to be a guy that is the head of the Colt collectors of Ohio that does a local show and I am hoping to let him take a look at it for me in 2 weeks. I don't really know much about these readings. I'm hoping the Colt letter will shead some light on this also. This gun does have some very nice case colors left on it.
Thanks
Tom