Originally I thought it was a clutch plate spring but all your bolts are in place. Good luck with the search.
I would suggest if nobody answers to look at Ducati Omaha fiche for your bike. They will have an exploded parts diagram for the clutch side and you might figure out that way.
09 Aprilia RS125 plated< NEW info> Now a 144 and back on the road!
06 Paul Smart Sport Classic NFS ever.
08 S4RS Tricolore #081 NFS ever.
The pink Monster has moved away.
97 900SS CR
72 Norton Commando 750
03 KX60 with S4R rear shock,Honda CB350F, Hodaka Ace90, 3x Yam-YGS1, Yam-CS3 200, Vespa small frame, Gilera 106, Puch Sabre, Puch 50 Boy Racer, Benelli 250, Benelli 360, Honda CB350T, and many more.