Is there a screw at the very end holding things together?
It is in the form of the parent design of the French 1822, which both US (heavy & light) were derived from but it was not meant for the US. The blade cipher probably answers a lot of questions but I don't recognize it.
I don't know if you can post a larger image of the cipher and when you do, please rotate it to save others need to manipulate your images.
There is a slight chance that it was British made, as some were made by Wilkinson for Egypt. Those would have been produced in the early 1880s . Need to see the very end, hence my asking about a screw. The grip appears to have been redone.
Cheers
GC