Nice, but it may be a gennie, and not a conversion - since S&W made a LOT of them for the Brits in .455 for the Great War (IIRC).
They're more often seen converted from .455 to .45ACP (w/cylinder rear machined for moon clip).
The pearls are a nice touch, though - just right/enough to give it that little touch of class.
It sure looks like Christmas turned out to be very merry for you ! .