The book press below might not be pretty but I’m sure it’s plenty serviceable and would give anyone the amount of pressure they need to press up a few hedgehogs. I found it on this website. And it’s currently for sale.
It’s made from a pipe clamp- readily available from any woodworking store or big box building store like Home Depot. Most pipe clamps can be bought in the pieces and you then buy the pipe to mount the clamping pieces and the system works through leverage. After sliding the top clamp into place you then screw the turn screw to create the tight pressure. Because you can buy pipe in any length this is a great design to work with- the only limit to the stack is how high you want to go. I wouldn’t suggest going over 16 inches, but that’s a lot of books. Hurrah for a binder thinking outside the box and making something that works, is relatively inexpensive and provides more than enough clamping pressure for the home binder.