OK, I've been erasing this bit of thought from my last two posts but here goes:
Your pistol would use .680 (or smaller) dia balls patched with a thin cloth patch. It should be cotton and not more than .010 thick.
In the Dixie Gunworks Catalog, the only thing they offer is a .600 or a .680 dia ball. Speer and Hornedy doesn't list anything above a .570 dia ball.
Because your gun is a flintlock, it will need Real Black Powder, both in the pan for the sparks to ignite, and in the barrel for the main charge. The new imitation black powders like Pyrodex or 777 will not work well (if at all).
Dixie Gunworks lists the powder charge at 35 grains of FFFg but the FFg would work fine and produce slightly lower chamber pressures.
Because your gun is a unknown, I would suggest something more in the 20-25 grain load for the first shots.
The fact that your gun has a touch hole in the side of the barrel is a good sign. Most decorators do not have this.
Find a magnet and test the barrel and the breech plug at the back of the barrel to see if they are magnetic. If the breech plug isn't obvious, the tang which projects from the back of the barrel is a part of it. Test it too. If they are magnetic, this is great.
The Cock (now called a hammer) needs to have a flint in it, and the flint should be sharp. If your gun has this, great. If not, you will have to buy one. It should be about as wide as the frizzen (the L shaped movable thing the flint will hit to make the sparks). The flint should be held in the Cocks jaws with a piece of leather wrapped around the top, the back, and the bottom of it to protect if from the jaws.
If you have this, bring the cock to "full cock", close the frizzen so it covers the pan and pull the trigger. (note: aim the gun at something which you don't care about. Even though you know it's unloaded, never take a chanch that it might fire.)
If the flint produces a bunch of sparks while it knocks the frizzen open, you have a working gun.
Let us know what you find.