The gun is marked Manton but is a screw grip and has patented engraved around the thumb lever as is common in other Webleys. Manton and co must have sourced the action from Birmingham. The engraving is sharp as is the checkering. The barrels may have been re blacked as they are in better shape than my photo show.
Through lugs not a best gun but in fit and finish a pretty good one.I will pull it out tonight and look at the lower rib to see what the small screw is.