The author remixed this model.
Modified lid for the MK13 case to make it as transparent as possible.
The base is only 0.2mm thick so it prints only 1 layer.
I removed the head cutout (for a monotonic layer) and made some side cutouts to make the lid easier to remove from the case.
Use some clear PETG and set the first layer infill to “monotonic lines” to achieve the best surface. I really like the look with a textured sheet but any should work.