This design is for this power supply.
https://www.amazon.com/gp/product/B00UHI3NGS/ref=oh_aui_search_detailpage?ie=UTF8&psc=1

It should be printed with .2 layer height. There is a .2 mm layer on the bottom that covers all of the screw holes. This should give a nice clean first layer. I print in PETG exclusively and this assists with first layer issues.

EDIT
This is still a work in progress - please use v2.4 of the back case - some of the holes were misaligned.

EDIT - 2 V3.2
I moved the power cord to the bottom and stretched it out a bit. This allows it to maintain a thinner profile.

Prusa

i3 MK2S

No

No

.2

10