Mr Kelly

You note Custer using a revolver of a pattern used by the Royal Irish Constabulary. As the whole of Ireland was controlled by the British state, perhaps it is the nickname of "British BulldoG" which was synominous with all things British or English in this matter. Until the end of the Irish Civil War in 1921, all things of an ordance nature would of been purchased by the Home Office based in Whitehall, England.
Regards
John