Flli Peitta is an Italian gun maker specializing in reproduction black powder and single action guns. Imported in the US by several retailers and distributors.
Seek the services of a gun smith.
Try gun shops, gun shows, want ads.
Chances are that if you overload the charge in a revolver style black powder pistol, you can blow up the cylinder or blow the barrel off the end of the gun.
In the technical sense no it is not loaded via the muzzle of the gun, black powder revolver is accurate as terms go, but they do fall under the blanket of "muzzle loader" in general terms.
I was getting one of my colt 44 black powders repaired and the ameture gun smith that was helping me out offerd $100 for one of them. Mine are in really rough shape though, they are functional but in rough shape.
Black Powder.
The question makes no sense.
To the best of my knowledge unless you are a convicted felon you can own a black powder gun.
The NRA web sight www.nra.org has links that can answer for sure, but I know here in FL there can not be a gun in the same residence as a felon, black powder or not. Check out the sight for sure, they have up to the second info an the subject.
Chinese
I imagine state laws vary on this but in Texas you do not have to call anybody to transfer a black powder gun.
There is also a gun called a Black Power Revolver.