This is a case for my 22 × 24 cm enclosure: https://thangs.com/mythangs/file/1533365?source=Recent

You can easily change the colors in your slicer, and assembly is very simple.

Just use the reference image and slide each part into place as shown, then secure everything with glue, or a similar adhesive.

The design is symmetrical, so you don’t have to worry about orientation. Just make sure the half circles are positioned at the top.