I have a pair of devices that I'd like to mount in boxes to protect them
and make storage easier.

They each have a footprint a little larger than an A4 sheet, and they're
about 3cm thick.

The box should have some kind of lid, to protect the control surfaces.

One of those foam-filled toolboxes would be suitable, but maybe there's
something a little smaller, cheaper and less ugly. I'm sure I've seen
wooden IKEA boxes with lids that could be adapted, but I can't find any
now.

Daniele