Dunno if you have a metal fab outlet like Alro Steel that sells mill ends, overruns, orders never picked up, plus regular stock that can be ordered. If they don't have it, you don't need it.

The outlet I visited had a bin right inside the door with small scraps of plate in different small sizes, like 2", 4" etc and short ends of round stock. IIRC, they were a few bucks each; counter guy just stuffed my cash into the jar next to the coffee machine.

The scraps need cleaning of of the shop grit, preservative - just let them sit in a tub of solvent then scrub with steel wool. Tuned mineup with a #120 belt in the sander/gokart until I got to bright metal, and got any burrs off.

These steel pieces are helpful for building, squaring, weighting a reshape of a warped frame, etc. Could also be used to weight down a container.

Another idle pastime project is to check your rattle can caps. A few brands of household and automotive paint (innaday, haven't bought in a while) would fit a jar of MM or Pactra. To keep them from tipping, fill the outer ring with those leftover nuts and screws that old guys are so fond of, then mix up a batch of old epoxy and fill. Fiberglass resin works, too. In an hour or so, you have a cheap tip-proof holder.