I have a solid ivory chess set (probably illegal to have it now) I won in a tournament back in the late 60s. I never could figure out how a dumb ole boy like me could beat all of those smart guys. {;o)
If it's that old, it's legal for you to own and sell domestically, generally speaking - the only thing you can't do is export it under the Endangered Species Act. If you could show that it was more than a hundred years old, you'd also be able to export it. FYI ;)