What exactly is “Copyright limbo?” I would think it might mean a situation where a work is not public domain, but there is no living person or entity with a clear copyright, so a work can’t be reprinted by anybody without breaking the law.
But these books aren’t in that situation. What they suffer from isn’t limbo - it’s obscurity. They’re already books, and you can probably scrounge up a copy by scouring used bookstores or eBay. It’s true they aren’t available digitally, but that’s not the same thing as limbo - some of us old people can still work the organic cellulose type of book, and would be happy to show you how.
Reprinting old books in new format is kind of cool, but scaremongering doesn’t really help. If your kickstarter fails, these books aren’t headed down the Memory Hole - unless some of them belong there.
