Found this 2+ years old model in Printables. Unfortunately no stl-files on board, only step and f3d and a gcode as well.
In order to modify thes files to fit my Prusa MK4 I could extract the step files and load them into TinkerCad.
The holder fits the new Prusa MK4 on the backside of the reinforced frame. Available threaded holes in the frame are being used, only need of three M3x16mm screws. Countersunk type (Flat Head Type). Four self-tapping screws (ca. Ø2mm) is the other stuff you need.
The (black) holders need support, no big deal. They are easy to remove from the holder. I put some glue between (black) holders and case halves.
Tip: If you melt the black holders with a soldering iron from the inside of the case, they won't fall off.
Everything printed in PETG. Parts fit together seamless. Happy with the result.
Edit: 06-Jul-2023: due to the holder coming a bit lose in the upper part I created a removable clip that keeps the holder better in position: https://www.printables.com/de/model/521541-additional-fastener-for-raspberry-pi-case-for-prus
I installed Octoprint on the RaspBerry Pi 3B+, 32GB micro-sd-card. Performance is more than enough.
Explore my other Printables: https://www.printables.com/de/@Tritschi
The author remixed this model.