Commodore Vic 20 and Commodore 64 wall mount.
This is just the right side, so mirror for left site.

I felt the middle support wasn't really needed and also tightened up the fit a little bit.
I printed at 20% infill, but might bump it up a bit.

This is a remix from https://www.thingiverse.com/thing:398515

Creality

Ender 3

No

No

0.2

20%

Any material does the trick.