You might want to go back a check Seller's book, Chapter 11 is titled Conversions. It goes into quite a bit of detail on the converstion guns, and on to explain how the early 74's were nothing but converted from percussion carbines to cartridge rifles.Thanks everyone. I was looking for a source and checked through Sellers' The Sharps Rifle and didn't see anything about conversions. The rifle itself has a buttplate cut out for a patchbox, but there is no patchbox. That also suggested that it was assembled from Civil War parts.