eBay sells them, but you probably wouldn't get what they're worth.

If they really are valuable relics, you might also get a good price from your local bookstore.

elibris.com or abebooks.com are both places that real book conisseurs go.

If you visit New York City, visit Alabaster on Fourth Avenue.

If you're in Berkeley, go to Moe's on Telegraph. They'll pay the big bucks (if you have the real thing).

i sell on amazon, but they take commission.