I can find only two Joseph Bakers. One at Rowley Regis in Staffordshire circa 1854; so seems unlikely, and Joseph Baker, Norwich Street, Fakenham, Norfolk 1890 to 1905 and then trading as Joseph Baker & Son from the same address until 1909. If that's your man then it helps to date the gun also to between 1905 and 1909. It would probably have been made in Birmingham and finished to Baker's specifications and retailed by him. What do the proof marks on the barrels say? This was in the period before compulsory Nitro Proof and would only have been proofed for nitro on request. Lagopus.....