A spectacular secret stash of movable books by Corrie Allegro and his wife in Victoria, Australia is definitely worth checking out. Many exceptional examples dating from the 19th Century, along with a nice overview of the movable book development through the centuries.
From their site: The Allegro Movable Book Collection is Australia's largest and most comprehensive collection of movable and pop-up books covering over 300 years of published history. Corrie Allegro is releasing books from this collection to the public, collectors and institutions. This book site will contain articles, news and related links to the genre of 'movable' books. Simply click on the headings above and browse the various stories and articles on movable books. Articles will be added regularly so don't forget to scroll down the lists.