What toolbox do toy have?
If you have a snap on, look at their industrial workstation/stationary cabinets.
They use their regular toolboxes with no caster but a solid toe kick base that I'm willing to be bolt on in the place of the casters. You may be able to buy that part as a replacement piece.
If you can fabricate, then making feet or a base should be very easy
I like the hockey puck idea but I would be tempted to stack 2 pucks drilled in the middle and just countersink the bottom one. Then bolt them on
Bob