More kerbside/dumpster gold.
Imagine if you will, what the castor bracket(pic #1 on the left) would have looked like, wheel at that angle jammed hard against the inside leg, base still flatish.
Been thumped with a car or forklift shaped hammer.
Wish I'd taken a before pic, description doesn't do it justice.
In the press to rough it somewhat back to shape. Pilot the pin, shave off the rivety bit and disassemble.
Panelbeat bracket, check wheel and bearing, drill, tap, suitable fasteners, reassemble.
One of the swivel castors wasn't even from this unit, original base still bolted in place with another broken castor sans all the loose ball bearings sitting with it in the bin.
As luck would have it, the oddball(pic#4 on right) had a sealed bearing on the underside and a thread + nut under the splayed end of the pivot pin on the topside.
Grind off the splayed end, washer in place of the loose ball bearings, straightened the existing baseplate, add another washer and nut back on. Weld nut in place(alas no detailed pics of the inner workings, I was in the zone man).
Turned out tighter(not wibbly wobbly like they usually are) and freer(smoooooth) than the other original castor.
And into the arsenal it goes.