There are a couple 1763/66 French muskets out there - the preacher carried one, as do the Continentals and at least one other member of Martin's band (look for the steel bands holding the barrel to the stock). PC for the Continentals, who were issued 1763 Charlesvilles given by the French, but iffy for the militiamen - they were just being replaced by the model 1777 in France and are unlikely to show up as surplus. An earlier model French musket would have been more likely, as would an older Spanish musket - the Spaniards still owned Louisiana at the time.
Martin's rifle: made by Frank House. Since it is iron mounted, it is really not PC, but is otherwise OK, I think.
Gabriel's rifle: Chambers York kit with a sliding wooden box. Very PC, and it is not too farfetched to have a PA built rifle in SC, carried down the Great Wagon Road.
Fowler: Made by Mike Brooks. PC, and representative of probably the most common type of civilian firearm - there shoud have been more of them!
Don't know much about the pistols.
Hope that helps.