I built this two-part case for my midipal. It screws together using 4 M3 screws. It fits very well, the screen cutout could be made 1mm smaller.

I used through hole leds, but the smd leds should also be visible through the holes.
The OpenSCAD file allows you to enable some optional things such as a text/logo on the front (although the logo png is not included here). The uploaded stl does not have a cutout for the switch as I have bridged the pins for that, but you can enable the cutout and a (untested) battery holder in the OpenSCAD file (or using the customizer i guess).