This is the stuff to use if you want to strip them. Like I said in the PM, if they weren't media blasted, they might be salvageable.
This is the only stripper that will actually dissolve the powdercoat and leave the metal exactly as it was before stripping, and just needing to be washed off with fresh water. Would probably take about 3 gallons at least though to submerge the wheel center.
Eastwood Powder Coat & Paint Dissolver