I concur, African Trade piece, likely made in the 20th Century. If you study American and Europeon guns from the 18th and early 19th Centuries you can tell that this is not one of those. If you notice it has somewhat crude features yet at the same time "modern". Examples are the round headed nails, modern stamping in the stock,the modern looking screw heads, modern screw pitch and the overall plainness or lack of artistry in say the lock. That odd breach is another clue. It looks like basically a tube barrel with a reinforced breech, very crude and very cheap.The crudeness and economy of construction suggests the African Trade although pieces were made for South America as well.
Guns like these were produced in Belgium, some with left over musket parts into the 1950s.
I have no idea where this one was made.