GS500f 2004 alternator flywheel rotor compatibility

[Uncle Honj]

I have removed the flywheel, trying to find a replacement as one of the 6 magnets has detached itself and broken up (Goat's syndrome?).
The stator and shaft end look as if they'll go again, but I haven't managed to find a 2004 replacement (or 2003-2009).
My question is, are older flywheels compatible with the 2004 engine? Part numbers are different, some older ones seem to have 3 magnets, and a new one is around £200 here in the UK (ouch).
Any responses welcomed.
Cheers
Uncle Honj

[gsJack]

Took a look at US parts fiches and 01-02 rotors are same part number as 04-06 part number so there is now one number for 89-00 GSs and another for 01-09 GSs, except no 03 were sold here.  Pictures in parts fiches show all have 6 magnets but can't always count on fiches drawings being up to date.  Don't know what difference is between the 2 part numbers or if they are interchangeable.