There is a return spring for the pedal available on ebay.
I can't find where it goes though, although mine does not have one, 9Mine 1997) the pedal is at the correct hight, level with brake pedal.
The adjustment for the pedal hight is down at the clutch arm, (opposite end to pedal) a nut & a locknut, these are only for adjusting the pedal hight.
There is no other adjustment for the clutch.
Gerry
September 2015