1974 Kz 400 Clutch friction plates replacement

Hi sorry its me again
I put the wrong oil in my 1974 Kz400 and now the clutch slips I ordered some new friction plates which said they were for a 1974 these were too wide across the face and did not leave room for the strange sort of spring shim that fits inside the circumference of the friction plates which I guess helps to disengage the plates from each other, I ordered some more but these are just the same
In the manual the clutch from 76 does not have the spring shim thing.
Has anyone rebuilt the clutch without the spring/shim? 
Thanks in advance 
Andre  

did you try cleaning the friction plates with a solvent? brake cleaner. or varsol. or whatever.

Hi Thanks for the reply I did try that but it still seemed contaminated so I thought I would try new plates