I can get an original printing of the British printed patent for this. My colleague has it. It will likely have more info. But this one has no drawing. It costs me like $150 for each one I typically buy from him.
A drawing would be wonderfull because its a patent filed in 1860, 5 years before the patent of Eugène Lefaucheux about his multi-shot, double barrelled revolver.
In that patent he is saying that nobody else in Europ or in the world has filed before him a double cylinder and double barrelled revolver.
It would had been interresting to compare both drawings …