The markings on the tang of the buttplate, "26 LSt. over B and #1644" demote the Prussian "26th Landsturm Regiment but it is not a military gun, it is a "trade" musket made in Belgium for sale to native populations in Africa where the indigenous people were not allowed to have modern arms. This particular one has been made with surplus military parts, new and used, that were in inventory. The barrel and lock are the only parts made specifically for use on this gun. Most parts, the trigger guard, and bands, are of French style and the buttplate probably came from a Prussian M1809 musket as is evidenced by the Landsturm markings. The musket this buttplate came from had been stored for Landsturm use in the mid-19th Century when the Prussians went to the Dreyse needle fire breach loaders. By the 1870s, these guns were surplus to even the Landsturm and the guns were either sold or broken up, thus this gun had to have been produced no earlier than the last quarter of the 19th Century, say after 1880 and maybe as late as the time leading up to WW2.
These guns were heavily imported into the US post-WW2 as decorators and really received a boost in popularity from the Davy Crockett craze of the 1950s.
As a side note on the Landsturm, they were untrained elderly or unfit younger individuals who were to only serve near their homes in case of invasion and received third class arms in most cases - they were classic "speed bump" troops. They were not actually activated until WW1 when some saw front line service but most guarded rear areas and POW camps in Germany.
