Wow, Scott, are you actually saying that even though Clawson doesn't mention the use of any narrow serrated hammers in Colts in his book, anywhere, and when he does mention narrow checkered hammers he says around 1.7 mil serial....you are saying that a serrated narrow hammer could be right in a gun that is 80,000 serials earlier than mentioned in the book? Do you have the actual equipment to do a forensic tool mark examination to see if the parts have been together and are you a recognized expert in such examinations. I'm not referring to a Colt appraiser but a forensic tool mark examiner. You know of course that if you fire one round through a pistol with the parts in place the internals will show the marks that would indicate they have always been together or at least been together prior to the examination.
In my collection I have 3 Colts that are undisputed as to being totally original except for possibly magazines. A 1.66 mil, a low 1.69 mil, and both have wide checkered Colt hammers in them. I have a high 1.69 mil which has a narrow Colt checkered hammer in it. dmthomp32's pictures don't look like a serrated Ithaca type hammer but rather like a narrow Colt checkered hammer. Since that is closer to the 1.7 mil serial that Clawson used as an approximate time, I would not doubt it as original from Colt.