Your gun went through the Proof House in the 1896 to 1904 period.
I have an E Roberts single barrel 20 bore listed at 141, Steelhouse Lane. Brown's Birmingham Gunmakers has an Edgar Roberts list there from 1903 to 1923 and at 5, Steelhouse Lane from 1897 to 1901 so that will narrow the date of your gun. It will have most likely have been retailed and/or finished by Roberts rather than made by him. The style of the gun is fairly generic for the Birmingham trade around that time. Looks like a good solid useable gun. Lagopus.....
