Sgt. George:
Your rifle most probably was manufactured by Aceros De Hispania, in Spain. In this link there is a picture of their Kentucky Rifle. You can go to their home page and obtain an address to write for more details.
http://www.aceros-de-hispania.com/gb/infer.asp?ac=10&trabajo=listar&pa=armasI would strongly suggest that you invest in a couple of good black powder muzzle loading books, one by Lyman which will give you all load data and another by the old pro Sam Fadala:
* Lymans Black Powder Handbook and Loading Manual
* The complete Black Powder Handbook by Sam Fadala
* Muzzle Loading by Toby Bridges
There is a lot to learn.
It goes beyond just shoving a patched ball down the muzzle:
Briefly, you can shoot traditional black powder which is not easily obtainable because many stores do not carry it due to storage restrictions. Or Hodgdon Pyrodex substitute for black powder of Hodgdon Triple Se7en which is much cleaner burning with less residue.
Youll need shooting patches, linen is best, cleaning patches, balls, a variety of accessories, possibles bag, powder measure, powder flask, powder horn. You'll need to know how to clean out the flash hole, how to prime *( FFFFg ) and what to use. How to knap a flint. How to install a flint. How to clean the rifle and preserve it.
You'll need to know the aerodynamics and trajectories of round balls and their limitations and terminal energy.
So far as loading is concerned I suppose you know that you cannot use smokeless powder at all. And that black powder and the substitutes have different weights and powers so they are never measured in a scale by weight but rather by using a powder measure by volume only.
You'll need to know how to handle a mis-fire *( soak the barrel in water for 30 minutes before fishing for the ball or other obstructions ). How to use the various retrieval accessories to remove round balls and patches.
Mid-South Supply is a good source and Cabelas has a 2005 Shooting Catalog that has just about every thing you will need.
Good Luck:
Bill Tibbe