Have been pondering this lately also. Need to store (in ute, any lock-ups on jobs) four bars up to 42", multiple quantities of chains in each of about 4 sizes, spares, digital angle finder, etc. Currently, I have a MDF box a bit like a rifle case I made up but am not happy with it not being weatherproof, and chains being all over the show.
Current idea is to make another box and lid, from rigid PVC foam board, and have roughly 1" high internal dividers spaced about a 1/2" apart, running the length of the box. Chains can slip in between these without tangling and I can keep the various sizes and blunt or sharp apart.
Also considered about 1" clear pvc tube for the chains, and just thrown them in the box.
Another idea, and my preferred one if I could actually find something like this here and it didn't cost so much, is using a flat back aluminium heatsink extrusion long enough to run the length of the box, for the chain dividers in the box:
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