try here http://www.issler-felgenservice.de/index.html he has a good rep amongst the car dealers, cost i do not know but would appreciate some feedback if u get a price.
On Blauenstraße in Weil am Rhein, just behind the Mercedes-Benz dealership, there are two tyre places. One of them (can't remember the name) does alloy refurbishment for around €100 per wheel, from memory. You could also try Euromaster, opposite McDonalds in Weil am Rhein (just past the Rheincenter).
Having just checked Google Maps, I think it's:
Wolf Reifen
Blauenstraße 73
79576 Weil am Rhein
Deutschland
+49 7621 72093
otherwise it's:
K 1 Autoservice-Reifenhandel GmbH
Blauenstraße 71
79576 Weil am Rhein
Deutschland
Thanks very much!
AVOID!
Its a bit out of basel but try this place
I used them before and will use again, they were one of the few places that could provide a diamond cut finish.
The other places mentioned here are just agents and send the wheels away.