Unknown .31 cal spring air pistol

Unknown .31 cal spring air pistol 

With thanks to Wes.

John Griffiths, author of the Encyclopedia of Spring Air Pistols said of this pistol:

(a) If has to be muzzle loaded then I would say it is cork firer. , The barrel has a large bore for a pellet or dart firing gun, particularly as the size of he pistol and the and method of cocking  could only provide very limited power.

(b) Much more exciting, if it is a breech loader and the barrel is broken for loading, then it could be an example of the pistol patented by O.W.Horr in 1873  (US patent 139,391).  This would  be the only known example and worth a small fortune !