Quick Correction. It seems the last ipad synch deleted the preview from ipad. The book I was working on is no longer in iTunes and has been trashed. How do I access previous iPad back ups? These seem buried very deep in ML's OS.
To work further on the book you need the .ipa file, which I think would only be on your Macbook Pro. Search your drive carefully for anything with that extension. Do you have any kind of back for your Macbook stuff, time machine or otherwise?