So in the course of making this more "compelling" (realistic), I learned quite a lot about animation, gradient fills, double buffering and so on. By the end of a day, I was just starting to implement a nice animation of pages that curl from the corner (building on a nice Java example by Arnoud Philip), when I remembered that I didn't really think a book was the right metaphor anyway. It was surprising how far I had been distracted by the appeal of naive realism. I'm still pretty certain that physical simulation does help users to become immersed in the abstract world (the physical realism of the touchscreen swipe-to-scroll is what really convinced me), so I'll return to this in future.
However, I'm not going to spend any more on the book. A stack of index cards might be a better starting point.