That is an ambitious conversion. One of my books shows a modern Paterson conversion - real custom work.
I wanted a barrel with a true .357 groove diameter for my project. Took a '51 .44 barrel that bubba had messed up, and bored out the rear portion, cutting the barrel off flush. Sleeved a .357 barrel into this breech section. Haven't mounted a front sight yet, but it is ready for test firing.