Pristine Alloy Wheel Refurbishers Ltd in Milton Keynes do an excellent job back to factory finish / profile whether powder coated or diamond cut. They redid all my 6 spoke alloys on my 2003 Elite - not because they had kerb damage, but they were flaking in the inside edge due to alloy corrosion. Did a brilliant job. They collected the wheels too and returned them when finished at around £85 a wheel.
They used to do all the 'proper' refurbs (not the cheap crap wheel cover ups) for my local Audi dealership and did my Omega wheels for me booked through Audi.
Demon Wheels in Preston do a first class job too, reprofiling to original if kerbed and a perfect colour match to the original at around £90 per wheel.
Good wheel refurbishers are everywhere now, but I would go off recommendation or go and see some of their work and the set up first.
You get what you pay for - a cheap 'man in a van' job or a proper back to original finish.