The bottoms are just held on with glue or nails? It won't work if you fill these with steel hardwares, the
bottoms will fall off. Best might be to give 'em a bit of finish (shellac or prime-and-paint) and use 'em loose on
shelves, for things that'd roll off otherwise; one for epoxies, one for wood glues, one for light oil, one for greases,,,
They were made to hold collections of items used by the artisan, so as to organize his work (first step, use tools
and supplies in box 1; second step, put box 1 away and work from box 2...). For that, they're ideal, like cigar boxes.
Also ideal for pencils, markers, calipers, notepads... lightweight items that just clutter the workspace otherwise...
I'd consider a wirework shelving to place all these... you can look through the shelves to see what's in the boxes.