Thinking of how I would build one. Top and bottom rails. Two posts going top to bottom. Inbetween there’d be a carriage with camera, light, and gripper. The gripper would have five fingers. One and five would prevent neighboring books from moving. Three would be a kicker, having the top of the book and rotating it down. Two and four would grip the newly rotated book. I might have to rethink this. Either all fingers have to do all jobs, or I need to move in my books two fingers from the edge of the shelf.
Spatulas.
Spatulas with an ability to rotate a bit.
Peter's stuff.