I have yet to release anything I've scanned and made into an ebook. Seems the way to do it is pay for space on an FTP-like site and then tell folks, offering a link. I could give digital copies to friends, if I had any who were ereader savvy or liked the same books I do. That's not happening at this time
However, I think it would be cool to try to contact an author about spreading their older work around. "Dear Sir/Madam, Way back in 1969 I really enjoyed ___ that you wrote. I just found an old copy in good shape, and I have scanned and turned it into an rtf file. I did this because no publisher has done it nor seems likely to. I'd like to give digital copies to my friends and others on the internet, if that's okay with you. If you'd like a copy, too, I'd be happy to send one to you...."
This assumes the author is still alive +40 years later (and some of the books I've scanned are in that +40 age range), and that the author is computer literate enough to want the file I made... However, it would be fun to say "This book has been posted with the approval of the author". Hey, the author might even want to take the opportunity to hear from old fans and give permission to post a link to a site or email eddress. It could be an interesting project.