Many thanks James for posting images of your Barrett retailed Lift Uplever. Clearly a Powell product based on their patent 1,163 of 1864 and a lovely gun if a little tired. You can see an almost identical gun of page 94 of Birmingham Gunmakers though this one is signed W. B. Barrett of Burton-on-Trent. Jim Ferguss gun was retailed by, I believe, Barrett of Thetford in Norfolk. Does anyone know of a connection?
James, when I was researching Birmingham Gunmakers Peter Powell told me they produced huge numbers of these Lift Uplever guns which were mostly signed by the provincial trade. When I asked just how many I was told they had lost count!