Unless he has late 72 spindles that take the bigger wheel bearings, the D100 rotors won't work.

I think Dr Diff sells spacer sleeves that will convert the early 72 and back spindle to big bearings so you can use the 73 up rotor.

It is also my understanding that they are now producing the 69-72 rotor in unicast so they are much less $$$ than the 2 piece rotors were but I haven't actually had one in my hands to confirm the bearing sizes.

Kevin