I took beepBot's original model, turned it into a box and transplanted the hinge from moeknows' wonderful Tardis ring box (https://makerworld.com/en/models/191153) onto it. The pin isn't quite as tight as I would like, so it might be worth scaling it up a percent, but it definitely works well enough.

If you are a Sonic fan, or are proposing to one, this box is for you! Post those proposal pics!