There are many other collections at the Lilly Library beyond books and manuscripts, including comic books, sheet music, and puzzles. If you find yourself with an interest collections that are not searchable through IUCAT or Archives Online, please feel free to contact me for a quick tutorial in how to use the collections.
Note also that there are book and manuscript collections that are unprocessed or only cataloged in print card catalog drawers. While I am happy to give you access to these resources if and when I can, I urge you to focus for the sake of ease of use (for all of us) on the wealth of material that is available via Archives Online or IUCAT.