There's a book you might be interested in. It's "Tyler, Texas, CSA" by William Albaugh, probably out of print but still available. They used parts from damaged guns, mainly barrels, to build new guns. The new guns that used Enfield barrels were listed in the production records as "Enfield rifles" and were .577/.58 caliber. I think you will find that the .45 caliber Enfield is a mis-identification of the Whitworth.