This is a small parametric universal electronics project case with PCB mount posts in FreeCAD (0.20.2). It uses very little parameters in the attached spreadsheet file (width, height etc.). Vents are automatically stretched and multiplied.

You can use small 3,0x16 mm flat head self tapping (wood)screws to mount both PCB and top cover. Printed on Mini+ with PETG. No supports needed.

Update: made a slight modification so cable holes can be of different sizes (and square). Added one extra model where the holes are in the bottom part. That is probably easier when mounting.