I once ground the rivets holding the two halves of the clutch together and removed the 6 rubber cush drives. Time and the hot oil hadn't done the rubber any good, they were as hard as glass, not a bit rubbery any more. I looked into ways to make replacements but nothing came up.
I came by another clutch basket with less backlash so I'm now using that.
My advice: carry on using it until a better one turns up.