requesting titles to add to iBooks Store when original publisher appears to be out of business

Apple can't do anything if the book doesn't have a publisher that's still in business. Even if the publisher were still in business, Apple still might not be able to do anything. If you are absolutely determined to have the book, your best bet would be trying to track down the author or their agent and make a request to them, but you likely won't get a response. You may not be able to get the book you wanted, but if you have a look at Amazon's recommendations for other books you might like, you might find another book that you'll love. I've been in a similar situation, so I know how frustrating it can be, but there really is nothing much us mere mortals can do about it.

I originally overlooked your comment about new print books being available. In this case, it may just be the case that the publisher hasn't published an eBook edition, and that would then be far outside Apple's ability to remedy without cooperation from the publisher. It's a fact of life in this digital age that not all books are available in eBook or audio book formats. It happens especially with old books, but even with some new books it still happens.

Your best course of action, unless you're desperate for the book, is just to find another book.

Hello,

If you’re in the US, have you tried BARD? They have a large collection of old books that they converted to Audio and Braille format.

If you’re not in the US, post your location and someone familiar can assist.

HTH and good luck.

Well, if it comes to ahead, 1dollarscan.com does an almost perfect high quality scanning service for a very reasonable price. You can get $1000 pages for $34.95. They scanned a very complicated history textbook for me and did it well. Let me know if you need more help with that