I too have a W Richards bearing Birmingham proofs. Mine is a side lever with a single underbolt. Barrels also carry a 14 mark, but the chambers are 12ga. Gun was proofed prior to the chamber marks. It is in very poor condition, I keep it because it belonged to my Grandfather. I personally do not believe my gun is of the quality one would have suspected from one built by William Richards so have no idea as to by who or where it was built.
From your description yours sounds like a higher grade gun than mine, hopefully it was by William.
