Mount for HomeMatic HM-OU-LED16 Status Display

I liked the simplicity of
https://www.thingiverse.com/thing:2788102
and the design of
https://www.thingiverse.com/thing:2229345
but needed something a bit more sturdy to resist the utilization of the buttons on the back. The design should be printable without support and contain screw holes to mount it to my IKEA Ivar shelf.
v0.8 was a basic fitting test but the sunken screw holes had the wrong angle (120°) and were not deep enoug.
v0.9 is the design I am currently using but I disregarded