There may be subsquent versions of the release lever - but the 'new & improved' modified one shown on the right above was standard issue in my 1980 car - with 19mm ball cup and all.
The '78s and some '79s had the 'orriginal' version - so I'm unsure what can be determined by removing the airbox - other than the important condition of the plastic 19mm insert.

 

and if you have the insert by the diagram...you have the updated arm...

 

Just checked the PET for both 85 and 90 models.
It says on the clutch control arm partnumber 928 116 832 07 for 85 and
928 116 832 08 for 1990.
And for both there is a comment which says 'dropped use 928 116 832 09' .
So it looks like you can't be sure to have the new version on any of our cars?
Question is there a visible difference between clutch arm 928 116 832 08 and the recommended replacement 928 116 832 09 ?
Seems like there could be mistakes done here causing noisy T/O bearings with premature failure

Cheers/Peter

 

BUMP

Any suppliers know the differeneces between a 928 116 832 09 and the (08 / 07) versions?