is powder coating any good? place in Barnsley is really good with alloy wheels
If you could get the stay clean enough then I think it would be worth a try, after all powder-coated alloy wheels seem to survive pretty well in harsher conditions.
The problem as I see it is that you'd have to blank off the screw holes as otherwise they'd end up undersized, and that would give a potential route for corrosion to get under the powder. Maybe Duralac could help here.