I’ve seen the tiny little wooden books that craft suppliers sell and gave it a twist. Using scrap pieces of 3/4″ pine I used varying sizes and used a 1/2″ double flute bit on the router table to give the inset for the “pages”.
Painted in different colors and gold trim, then mounted in different styles. It makes people do a double take when looking through the bookcase. The wooden apple on top was an after thought.