This is a box ment to be dificult to understand how to open when closed.Made with sketchup and converted to a printable formatTolerances of 0.1 mmYou can print full size on a 20 x 20 bed it two sessionsOr you can print it in one session scaling it at 95%
It is quite probable that you have to reshape the cover with a knife or sand paper to get a perfect fit.
I'm adding the original 3d model format to be editable.