Insert organizer for epic spell wars of the battle wizards. To fit the version of the game that I own, Panic at Pleasure Palace, I printed:
They fit flush on the original box, see pictures, but it took me some trial and error to get the box sizes right. I didn't want to waste a lot of filament reprinting them so they don't line up perfectly. If that bothers you the open scad files have parameters that can be changed using the organizer to tweak the dimensions.
The author marked this model as their own original creation.