The swingarm is finished in satin black and was done by a mate of mine who used to work at Buckley Enamellers, near me, so no real contact to help you as he no longer works there.
Mine was done as a 'favour' for £40 an took about a week to complete, however, he reckons that any enamellers would be able to carry out the work for about £80 and dependant on how busy........well how long's a piece of string?
His veiws on the 'powder v's enamel' argument are that enamel suits the swingarm better as its finish is harder wearing and less likely to lose condition, what with all the road crud and constant cleaning!