Notice the "P" stamp on the left side behind and above the cylinder. That's a government proof mark, and its presence suggests that this might have started out as a British Service Revolver in 1939 or 1940. The big logo on the sideplate along with the single line address points to the late '30s or early wartime years; before 1937 the logo would have been smaller and on the other side. I suspect this gun had a .32-20 barrel and cylinder substituted for the .38 S&W barrel that it would have carried originally. The jeweled treatment of hammer and trigger is not original, and the entire gun looks to me as though it was reblued at some point.
So: not a collector's item, but potentially a good shooter grade revolver for plinking and pest control.