Both Benelli dealers only have the metal based friction discs on stock which are rattling like a Ducati clutch. I don't know the material of the original ones but they seem to be entirely made of carbon fibre / synthetic resin composite in beige-brown.
My request to SURFLEX S.R.L. if they plan to manufacture again the original friction discs - made of an organic composite - in the near future got answered less precise with the following lines:
"Thanks for your request.
The friction disc for Benelli 900 Sei is still available, but unfortunately out of stock at present. The production is not scheduled yet, so it is difficult to give you a sure date of possible delivery.
Please ask again in some months.