What interests me ( I really should get out more) is that is has both a Crowned GR AND Birmingham Military Proof. The latter was only applied to so-called "commercials", that is to say rifles that were not built for HM Government.
So that lead me to: it was either a rifle that was taken up by the government at some time or sold by the government between the wars an thus needed "civilian" Proof.
Any comments on my proposition?