Do you honestly believe you're "suppressing art" if you fail to force the rightful owners if said art to go against their own will and instead follow your orders and desires on what others should do with what's rightfully theirs?
It sounds an awful lot like your are not as much interested in anyone's freedom as you're interested in imposing your personal will into everyone around you.
My opinion is that copyright should be limited to the lifetime of the author, at which point it goes into public domain. In this particular case, that would mean the books would have been in the public domain for a long time now and there wouldn't be a controversy over this particular issue.
But the issue could still arise if the author were alive. Imagine Dr. Seuss were alive today and made this decision himself. It's the same controversy: person/entity with control over IP makes a decision on distribution of IP, people get upset. But that's the deal - you want to promote the useful arts by granting limited monopoly rights over art, then you better actually grant limited monopoly rights over art. That means the right to not publish the art.
You say that eBay is preventing one private owner from selling to another private buyer, but what’s the alternative? To force eBay to facilitate the transaction? How is that freedom? The owner and buyer are still free to sell and buy this book, just not thorough eBay. If there is enough demand for this kind of transaction then the market will find a way to facilitate it. That’s capitalism.