On a 1995 S-Class 140 Series, are the alloy wheels painted or what. Looks like some sort of paint to me. Mine are showing signs of wear in the holes. Is it acceptable to sandblast and powder coat the wheels if they are painted? Or does this weaken the wheel. What is the best way to get them back to factory new looks?

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1995 S-350
370K + SOLD
1952 220B Cabriolet
39K kilometers + SOLD
1998 E300D
310K +
2012 E350 BlueTec
120K