Free is always good.
I salvaged this off a guy making a scrap run, he had an open utility trailer & the bed of his full-size pickup filled with hard junk. This heavy-gauge (red) box was in it. The grey steel chest of drawers, too.
I think it's some vintage cabinet from a commercial garage, maybe someplace where they stored parts like for service of auto AC systems. It had 5" caster wheels & solid rubber tires on it, two were locking. I removed those and added a 3/4" wood floor, and a masonite back. I also covered the wood top, replaced by a former owner, with another piece of masonite I had in the cut-off pile. The Harbor Freight (HFT) furniture dolly on-sale contributed its casters, I'll use the rubber 5" ones I removed on another project.
The box is 16 gauge steel, it has a spring latch and a hole in the single door for a lock cylinder. The door is on a pair of long piano hinges; the shape of the door is curved side-to-side.
I added a half-shelf inside, and cut-out part of the inside sheetmetal at the front to give more room for whatever is going to be stored inside. You can see the inside shelf had a deep piece of sheetmetal below it, that I cut-off, for more room access, evident in the second picture.
I'll probably throw this onto craigslist (CL), since I didn't pay anything for it, my big expense was buying an on-sale HFT furniture dolly to get the casters.
I included a shot of what the box looked like when I pulled it off the scrap pile (first pic). I also got a steel chest of drawers, again, free.
The chest of drawers was a light-duty steel cabinet, the drawers weren't on slide-out brackets, no ball-bearings, not heavy-duty. However, each drawer had three long bins, with snap-in plastic dividers, and the dividers were still in plastic packs. There were some items in the drawers, a selection of a few dozen wire crimp terminals, three rolls of teflon tape, some 1/8" L-angle brackets, a bunch of small nuts, bolts, and washers, etc.
I'll scuff-up the paint, use some grey Rustoleum, and make it look better, and probably put it onto CL too.