It cannot be denied this is a very handsome pistol, and with my limited knowledge of guns, I can only note that the St. Etienn inscribed on the lock with date above seems odd. The inscribed 'date' , then the stamped 'date' on the barrel with misaligned numbers seems incongruent.
As Fernando has noted, the 1847 date presumably intended to be a production date seems late for flintlocks, despite the fact that they remained preferred in many regions. In colonial regions such as North Africa, flintlocks and even matchlocks remained in use into the 20th century by tribal peoples, much as they did in Arabia and many other areas.
In frontier America, especially in wilderness areas, the flintlock remained of choice as it was easier to procure powder and fashion ammunition than to obtain percussion cap materials or cartridges in later cases. The flintlock remained somewhat universal in those kinds of situations.
This gun, incongruent as it seems in parts, might have been assembled in a trade situation, perhaps even in America where the St. Etienne guns were known to have arrived in number for trade in areas like St. Louis etc. From its appearance it looks more like an 18th century British gun to me, but I am not as familiar with 18th century French models. The script looks 19th century in style, so perhaps industrious merchant put this together for sale in American frontier? Just optimistic thoughts
