My gun is very close in serial number to yours s/n 4678. I forgot to specify, in my post, Schoverling and Daly were an American import company who went on to found the Charles Daly trade name. From what was written in the ledger my gun was shipped to them in the USA in the early 1870's along with several more. Here is the a link to the original post I am speaking of.
http://www.doublegunshop.com/forums/ubbthreads.php?ubb=showflat&Number=192992&page=15 I thought it would be interesting to find the American Advertisement. It seems it is harder to locate than the English one.
