Weinmann DP-18s are all powdercoated, duh.

You can try Jasco -- I'm not sure if it can cut through powdercoat, especially the thick crap Weinmann bakes onto those rims. If not they will have to be media blasted.

Either way, you want to buy a tub of Mother's Mag and Aluminum polish. At that point the depth of reflection is up to your level of persistence -- schlepping polish on with a rag gets tiring quickly.