Use your empty spools to create a miniature display tower. I used 4 empty spools to make an 8 level tower! Mirror and copy the half circles to make the internal levels. Work in progress...

Made for spools 200mm in diameter, with an 88mm central shaft diameter.

Glued together with gorilla glue and painted.

The only thing i would change in retrospect is make the spacers 10mm taller, as quite a few miniatures are taller than 60mm, but that would make the level heights uneven.