Thanks, Ivanhoe. Westley Richards No. 10804 is interesting in that it has the pull-lever, and from the serial number dates from 1865. WR patented his lateral lever in 1864, but was clearly still making the pull-lever action in 1865. Another example of this action on a 1865-dated gun is shown on page 6 of this thread (https://doublegunshop.com/forums/ubbthreads.php?ubb=showflat&Number=576857&page=6)

Joseph Matthews of Kendal (1847-1869) is on my list, but I'd not seen any mention of pinfire guns by him.