DH-
What's the gun? Is it a Daly?
I think this is the patent:
Abbey & Foster breech-loading, top-fastening shotgun, patent of April 25, 1871, No. 114,081
Any idea if it was ever patented in the UK?
BTW:
I did some searching and found myself a ways down on this page:
https://www.germanhuntingguns.com/archives/archive-lindner/It mentions that in The Gun and its Developement Greener wrote about how Rigby revived the Abbey breech-loader patent for Rigby hammerless guns.
Also, looks like all this has already been discussed here:
https://www.doublegunshop.com/forums/ubbthreads.php?ubb=showflat&Number=431255&page=8OWD