I think Gunman could be on the right track. Nothing to stop BSA selling a gun 'in the white' to be finished elsewhere and not that unusual to see a 'no name' gun waiting to sell into the Trade to be finished off and a name applied later. The 1 1/4 ounce mark indicates 2 3/4" chambers. That is the problem when trying to research English guns in that the name on the gun may be nothing to do with who actually made it. I have a couple with names on but no information in any listings on that name. Lagopus.....