ok, ive found this too
BRIDGE RECTIFIER
The bridge rectifier shown here replaces the lucas finned rectifiers fitted to British bikes from the 1950s to the late 1970 and will suit all models 6/12V fitted with an alternator except the later electric start Triumphs and Nortons.
The older Lucas rectifiers needed fins to disipate the heat generated, these are more efficient in rectifing all the current so need no finning and supply more current to the battery. Easy to connect, can be supplied with wiring instructions. Rated up to 25A £4.95 Pt.no.REC001
Dimensions are 30MM x 30MM x 23MM
this wired after the ducati regulator should do the job shouldnt it?
out of interest whats the earth malarkey change on the stator about?