Hello Down Under
I have not read through all your posts so let me apologize to you if some of my suggestions have been mentioned previously.
I encountered a couple of different clutch complaints over the years and here are a couple of suggestions I can offer.
1) The pushrod may be a ball socket, ensure it is properly seated in the clutch master (snaps in)
2) Pressure bleed the clutch in the reverse manner (through the clutch slave back to the reservoir)
3) Replace rubber hose near the trans, if not done already
4) Over center spring (only a suggestion)
5) Ensure the pivot points and or pins on the pedal assembly are not worn
6) Consider new nylon bushings where possible
I vaguely remember some sort of information on the clutch system for all cars. I will need to sift through my piles to find it.
Good Luck