Don't go away, a lot more info will be forthcoming. I have an article published in Gun Digest about the "Last Krag" at the house. I think it was the NRA/DCM conversion, these will not be the valuable original carbines, but conversions done at the west coast armory to move the surplus Krags out faster. I can not remember all the details, whether the barrel was given a full crown and was the 1903 Springfield sight used. Other gunsmiths and kitchen table mechanics could have followed the pattern, to make a handier deer rifle out of the original rifles.
Others will reply soon with the details.