khanh, with F.T.Baker I understand that Westley Richards own the name and used the London address there for a while. I've seen some cracking F.T.'s and he had a way of coding the date into the design on the trigger guard.
I suppose Norwich is as near London as it is to Birmingham. I have an interest in the Derby end of the Rosson business with it being local to me. The Norwich end was owned by one brother and the Derby bit to the other. There is someone compiling a book on Rossons and I have sent him all my research on the Derby end. When the book comes out and I get a copy I will mention it on this site for those who may be interested. Lagopus.....