Couldn't find a simple model for a permanent marker tray on Makerworld.
So I decided to make and upload my own.
Variant A: fits 4 small + 1 large marker
Variant B: fits 4 small markers
Because the caps of the large markers don't have the clip, you will have to store it with the cap side up.
Distance between peg and back of model is 5.4 mm (skadis is 5.5 mm thick) because I found a strong fiction fit is required to make sure the tray doesn't come loose when you remove the markers.