I am hoping there is a solution but........
Yesterday, I had to do a "Restore to new" on my iPad to see if it was a problem with the hardware and it turned out that's the problem.
While waiting for my replacement iPad to be sent out to me, I restored my iPad from the previous backup and it appears most things are back to how they were before I did the "wipeout" BUT I can't find the books, PDFs etc that were in iBooks before the reset.
When I first turned on the iPad I saw the list of documents but they were not in the "collections" I had filed them in and when I selected the "collections" nothing came ip and now I can't find anything there no matter where iBook and nothing comes up in search.
Before Ll this, I was going to do the iPad to Mac transfer but the application came up with a message warning there were incompatibility issues with the current IOS.
Any hints how I can hopefully retrieve my iBooks content?