lytta, Tiny False Book Box is finally finished and posted! It's very little, a single object that prints in place, and you can put tiny secrets in it. I've also provided a few templates for making a paper cover.
It's 1:6 scale for a small book (box), and 1:12 scale for a big, oversized book (box.)
This one is a paid design, available for $5 USD or to anyone who's subscribed to my Printables club: https://www.printables.com/model/846318-tiny-false-book-box