Paul why dont you just put a new rotor on.I have just got on from EBC cost $280 nz.Very shiny and round!.Zink plated steel Iam going to put a pair on the front as well next race season.Or you could try FGB discs in Waihi.Their email is sales@powermotorcycles.co.nz George got a rear rotor for his race RGV up here in North Is and it works fine.If you ask them they can do any pattern you want wavey drilled etc.Hope this helps