The style of the lockplate indicates it is most likely a Belgian made "Trade Gun". Many guns of this style were sold in Africa and other primitive areas of the world where the locals were prohibited from owning modern weapons. This pattern seems to be a twentieth century variation as earlier Trade guns were mostly made from obsolete muskets and stocks of old parts and are easily recognized as such. Some of these later ones will be found with a few old original parts (mainly hammers, triggers, etc, sometimes even old re-used barrels) but most were made new from the start simply to serve the African market. Cannot make out the proof marks but they are most likely Belgian commercial proofs from the early to mid 1900's.
In the 1950's Turner Kirkland started buying old guns from overseas to sell through his Dixie Gun Works operation. Along with the old ones he imported quite a few of these (the market for them was drying up as independence movements in Africa took hold) and they were in his catalogs for years. Other importers got into the act and they were still being sold into the 1970's in the US. The odd shaped lockplates are a distinctive feature and with a few parts changes could be sold as percussion or flintlock. They were virtually all smooth bore (I've never seen a rifled one but they may exist) and calibers varied, one extra heavy, large caliber one was even sold as an "African Elephant Gun" as used by native hunters. They were fairly common back then, some actually bought for shooting but many simply for decoration, especially during the Bi-Centennial.
