Jim , in addition to the thread linked above Nigel Brown shows the business becoming a limited company in 1936 at 4 Chapel Street, moving to 19 Old Hall Street by 1963 to 1982.
A photo of the proof marks may well help more precisely date the gun, and might also show some maker’s markings.
I have one of his SLE guns with chopper lump barrels, but no clue as to who made it for him save that the chiselling of the fences resembles guns by William Ford in Birmingham.
Sadly in those days the engravers almost never signed their work.
