Aha! Found it with some Googling...
"Ducati Clutch Bearing, genuine SKF double shielded 'Explorer' precision bearing. C3 precision class. Packaged in Singles. These high quality bearings made in Italy are the same product as fitted to Ducati motorcycles. 32mm Diam, 12mm ID, 10mm wide, and once fitted this bearing will give many years of prolonged service. Be aware of cheaper imitations, genuine bearings should always be used."
So I need a SKF 6201 2RS 32mm Diameter, 12mm Internal Diameter and 10mm wide.
Looking on ebay, I can buy a "Ducati Clutch Pressure Plate Bearing" for £7.99 + £3 postage.
Searching for the bearing itself, I can buy the right one for 99p + 60p postage.
Hmmm ... I wonder which one I should buy ...
Hope this helps anyone else!