I think you will find this is an OEM part supplied by a different branch of the Ducati company. If you check out:
http://www.ducatienergia.it/staging/...ternatori.html
and download the pdf under battery recharging systems you will find in that document an item described as "3 phase generator for enduro application". I think this or a version of it is the one used by GG. You may be able to find out which other makes (if any) use this system from it's description. I assume the sprag clutch bolts to the 6 holes on the back of the flywheel shown in the picture?
Hope this helps?