I have just spent a day on our nasty corroded and kerbed alloys, using a refurb kit from halfords (reduced £20). All it really came down to was cleaning, sanding, masking and spraying (they give you 4 tins of paint in the kit - matt silver). There was not enough paint, but the result was a big improvement. I shall just sand them off and spray them periodically, blow the refurbs, as it's so easy to kerb them anyway. Sleeves rolled up...get stuck in!