Thank you John...

What plastic spacer ring do you mean? There where the clutches and at the bottom the spacer ring is out of metal, as far as I know. But below the wave ring was sealing rubber, probably from the piston... or was there maybe a plastic spacer that is gone now?

Yes, the rear clutch retainer seems to be a late model (got a 3 tab washer + 2nd washer), the belleville spring is an early one, yes!

I will ask on the line pressure, but I said I want firm shifts... don't know if maybe the belleville was to weak? That would explain the scratches on it?! That the piston pushed the bellevile spring to much and it started to touch the planetary gears? Is that possible or how do you explain those scratches?