Note: " Minor Fitting". Not "Drop In"
Coffinmaker
There is no fitting when the cylinder is larger in diameter, it would not fit into the window of the frame. I was told by VIT, EMF Hartford (ASM) Cylinder would fit, maybe the Current GWII, would fit. My USFA is a USA Frame.
Likewise the Uberti Cylinder would not fit into Great Western Arms (1957) Frame, Colt 2nd Generation, and My EMF (ASM) for the same reason. The Uberti Cylinder was from a Navy Arms SAA BP Frame, All Steel, Cattlemen. Maybe Uberti has different specs for different Importers.
The Cylinders from GWA, EMF, USFA, Colt, are all interchangeable, perfect indexing, slight different head space, using the bushing that came with Cylinder. I finally purchased a 2nd Generation Colt, which required minor fitting, with a new bushing.