I was given a pair of unfired 1851 Navies by a friend a few years back. From what he told me and what I have been reading, they are 2nd generation 1851s (SN 228XX and 230XX). I don't shoot black powder and these are beautiful pistols from a good friend, so I was trying to decide what to do with them. Originally, I was just going to put them in a display case, but that wouldn't really be keeping with my friend's intentions in passing them on to me. What would be my best options for cartridge conversions? Everything I have read thus far has been drop-in cylinders for Uberti or Pietta revolvers. I have read about the tie to Uberti with the 2nd gen. Colts, but don't know enough, yet, to know which parts may be interchangeable. Thanks for your help.