Hello, It is quite possible to change the frame. For example, myself, I had 2 1851 (cal.44) brass casing. Armi San Marco Model + some parts of carcass from Uberti.
It did not take long to place the frame Uberti and mixed Armi San Marco elements. Of course, as with all black powder, must know how to play the file and adjust parts well. I now have a revolver that works very well, and far more secure than the Armi San Marco. Here's what happens.