For many years I had in my collection Tolley 10 G ball and shot gun #1749.The action of this gun was identical to your gun. in the case of my gun it was made for the Philadelphia International exhibition of 1876 and was of exhibition quality.It featured engravings of the Victorians era depicting the old West. For example on the under side of the action a settler is seen in hand to hand combat with a First Nation warrior.
The firing pin extractors are I believe Gastines patent # 2744 of1862
The locks on my gun were marked joint patent Stanton and Co and P Wilson #4824.The butt plate on my gun was identical to yours.The trigger guard on my gun was extended to provide a pistol grip effect as seen on many rifles of the period.
The exhibitors at this exhibition included W&C Scott, Greener,Alex Henry,Rigby,Purdey,Lancaster,Lang Webley,Green,Williams and Powell,Needham and of course Tolley!
I have often wondered what happened to all of the other fine guns that must have been present a the exhibition.
28 Countries participated including, Japan and China.More than 8 million visitors attended this exhibition!