Sorry George... I should have been clearer in my posting... I was speaking in general terms of serial number stamps on the guns parts... I have always taken them to be representative of the stamps of the period.
I don't own any Unit Marked guns, I have only examined those owned by others and of course, photographs... There is a wide disparity in the number stamps used for unit markings...
I guess the point I was trying to make was that in my opinion, this particular stamp and it's location doesn't resemble other unit marks that I have seen and I feel that while it may indeed be a military type "rack number", and I agree with Dwight, ...I don't personally know of any evidence that this type of mark could be verified as being placed there at any particular time frame.
Sorry if I confused things... <img border="0" title="" alt="[Frown]" src="frown.gif" />