Hi Keith,
I've seen this with not only muzzleloaders but with shotguns and centerfire rifles, manufacturers have either re-named or have had lower end models for the large retail chains.

BPI makes ML's for both CVA and Winchester branding. The CVA's are considered a lower line model as the Winchesters are dressed up a bit with nicer sights and stocks and the like. Functionally the exact same though.

Also, if I remember correctly:
Mossberg also made the "Maverick" line of shotguns for large retailers. The maverick was a low end MB500. Barrel and reciever were the exact same. Just lower end materials on stocks and triggers.

This is not to say a lower line rifle is any less safe than a higher end one.