These are the case specs for Malolo's case:
I'm using this Momentary Mini Push Button Switch.
The hole at the front is 7mm; added a teardrop to make the overhang part of the hole print cleaner.
I've added the bottom pieces as well, though they are completely original.
Using this pi-power-button script.
Please check out Malolo's original design, it's brilliant!
The author remixed this model.