Later 70s Kawi mag whhels (first ones) use a rotor that is near same size as 500 on the OD. They are about 5mm thick and drilled.
The stepped ID portion stainless part)is wide enough to drill for 500 carriers, may have to bore the ID bigger.
There is a chance the offset is close, in that case you can redrill to 6 bolt pattern.
They weigh around 4 lbs, I think the 500 disc is around 5.5 ish.
Just thought I would mention it, may help someone..
