Hi. Have you had a look at www.benelliparts.de?
Not sure if you have a series 1 or 2 650 but both oil filter (€13.20) and clutch plates (€95, hopefully not each) are on there .
Go to above site then select Benelli Teileshop.
Select the appropriate bike model (the 650s are right at the bottom).
Oil filter under Motorgehause. Clutch plates under Getriebe Kupplung in the pull down.
Click on the part number in the diagram to show prices and to be able to add it to basket.
If you get any trouble, just mail Detlef Burian (site owner) at [email protected].
edit: And welcome to the forum. Didn't see that this was your first post