Don't even go there with your thoughts my friend. I've cleaned up many barrels that looked awful and likewise have resurrected enough to make the efforts worthwhile. IF you intend to try to return it, do NOT shoot it--I'm sure you wouldn't do that though... But otherwise if you decide to keep it or can't return it... then take the thing out and shoot it with well lubed but tight fitting balls. Also if you can find some maxis, lube them and use some mild rubbing compound on them and let them help "lap the bore". It may not "clean up" as well as you'd like, but it will greatly improve over what it presently is. It may even shoot well enough for you to keep it.
(About looking inside a small bore)
It is kind of difficult to check a small bore muzzleloader anyway, as they don't make drop in bore lights small enough to fit in anything under about .45 caliber. There is a way around that. Take short lengths (about 1 inch) steel bar stock in appropriate diameters and polish the crap out of one end so it "shines like a mirror". Have a bright light with you and just drop your little mirror done the bore and shine the light in. It's not a perfect method, but it IS good enough to help you decide about the barrel, BEFORE buying the gun. Used to be able to buy a set of these mirrors (they are old!), but I don't know where you could nowadays???
You could get a Green Mt. barrel and replace the offending one that is on the gun now. Yeah, it would raise the cost of the gun considerably, but you'd have a brand new barrel.
I would still try to return the rifle for refund, and make it known that the bore is not in good enough shape for you. Remember do NOT fire it though if you intend to return it...
Shoot Safely and Good Luck!
WV_Hillbilly