Yes, what you have by the sounds of it is an original PH inert musketoon. It won't have a serial number or proof marks either, as in your case it was never a functioning firearm. If the barrel wasn't blocked, by virtue of its age (or lack of it) it would be on-ticket. I have both inert and live PH ones, and they are very nice
Bluing on my inert one is perfect, so possibly your one suffered a mishap previously or has been re-finished (though I don't know why it would need it).