I agree with American Made. And it may be a much later gun. Now that I see a better picture of that stock, it could easily be an early 20th century gun. Those Back Action locks were being sold in hardware stores well into the 1940s. A lot of inexpensive single shot shotguns were built on them, and you also see some DB shotguns using them that date well into the 20th century. I was told many years ago that these kinds of locks were being exported to Africa and India where ML guns were still popular, and often needed new locks to replace those that wore out. I am not sure where they were made, but it certainly could have been Belgium, with the London marking on the lockplate a come-on to suggest it was made by the English Best Gun makers in that city. ( Without something to identify the origin, it could be London, Ontario, or andwhere else there is a " London" where someone could rent a Post Office Box.