Hello again, I'm guessing you found a bike then?
I have a spare headlight from Ebay, took an AGE for a good one to come up, but they do. Signing into Ebay.de and Ebay.it specifically can reveal some interesting results too.
I think the OEM Ducati ones are a one-off special (but also for others in the SS and 851/888 series).
However, I'm sure I remember someone saying an oblong headlight from a similar age Yamaha could be made to work, FZ750?
Quite a few on Ebay including one brand new one: http://www.ebay.co.uk/itm/BRAND-NEW-...-/271833489728