The vast majority of muzzleloaders on the market today are replica muzzleloaders and their quality runs from superb to barely above "Junk" status.
To start with, check out the "Gunbroker" website on a regular basis:
http://www.gunbroker.com/Black-Powder-Muzzleloaders/BI.aspx
You will see a lot of replica arms advertised but also occasionally an original gun for sale.
Keep in mind that some of the guns advertised on Gunbroker are modern "In-Line" muzzleloaders which have no historical significance as they were only invented in the 1970's to allow modern deer hunters to take advantage of "Muzzleloader Only" deer seasons.
Google "Lodgewood Manufacturing" as they sell originals, replicas and have parts for original guns.
Send a Money Order for $5.00 to:
Dixie Gun Works
1412 West Reelfoot Avenue,
Union City, Tennessee 38261
They will send you their
688 page catalog. While DGW handles mostly replica firearms and replica parts. They also have a lot of information about shooting muzzleloaders in their catalog, so it is good for a reference book also. DGW also does have a list or original firearms they have for sale. In your order for the catalog, you can request that they send you that list of original firearms they have for sale. Their catalog is a definite "must have."
You can go to the North-South Skirmish Association website:
www.n-ssa.org/
And from there go to their Bulletin Board. They have several different "pages" that have a lot of information about shooting original and replica Civil War military issue firearms. They also have a "Buy, Sell, Trade" page on which original firearms are occasionally listed.
Also Google:
S & S Firearms, Glendale, New York
They sell original and replica parts for a variety of muzzleloaders and replica firearms.
Cabela's sells the Pedersoli line of replica firearms. They have "in stock" replica '61 Springfields, Enfields, '59 Pedersoli Sharps Carbines and Rifles, percussion pistols, etc.
If you decide to buy a replica rifle-musket the BEST is the Pedersoli Naval Rifle Enfield. The original Naval Rifles were so accurate that at British NRA target matches in the 1860's, any competitor using a Naval Rifle automatically had 10 points deducted from his final score because the Naval Rifle was recognized as being much more accurate than a regular, P-53 Enfield!
The Enfied Naval Rifle was also the "Rifle of Choice" and issued to Confederate Sharpshooter Battalions (when they were available.) In actual fact, the Union also purchased and issued a lot of Enfield Naval Rifles during the Civil War.
http://www.cabelas.com/product/Pede...+and+muskets&WTz_l=Header;Search-All+Products
One good thing about Cabelas is that they have a very good return policy. IF you are not happy with something you have ordered from them, they will replace it, no questions asked.
Tim Prince operateS "College Hill Arsenal" and he deals exclusively in ORIGINAL guns. While they are pricey, Tim includes a complete description with every firearm he lists. You can learn a lot just reading his descriptions. He also keeps a lot of guns that he has sold up on his website so you can read the descriptions of the history and condition of the gun, just in case you run into anything similar.
http://www.collegehillarsenal.com/shop/product.php?productid=1118&cat=9&page=1
Some of the other original dealers are: "Rock Island Arsenal," James D. Julia, " "Shiloh Relics." You can Google their websites.
GOOD LUCK!