I'll start it out - -
- - - By stating what seems obvious to me.
Single shot, underhammer percussion "boot top" pistol. Old style rifling. Damaged condition but certainly subject to restoration. Probably worthwhile, too, though I don't know what a collector of this type arm would say about that aspect. Nice exterior condition.
These were really pretty neat pistols, given that they were only one-shooters. The underhammer made the pistol far sleeker than those with the lockwork on top.
Historically, the window of production of percussion single shots (and double barrels) was fairly narrow. After percussion was well established as a method of ignition, the perpperboxes and revolvers followed on soon.
Hope some other member can come up with information of the maker.
Best,
Johnny