A wall mounted case for an old mATX board to give it a second life as an eye-catcher.
I have split the design to fit on the P1S plate and tried to reduce print-time by splitting parts so little supports are needed.

Use threaded inserts and screws and/or glue to join parts. Use the spacers that came with your mobo to screw it to the baseplate.
Fix your PSU with the screws that came with it.
Feel free to modify cover-design, height or any othe aspect you might want to change.