Lost 3/4 of clutch peddle

My money would be either on the rubber piece mentioned above or a split in the Z bar tube.

Before I bought my car it had the exact same problem. The Z bar had split & was spreading along the split. This kept the arms from traveling the full distance. The PO took it to a shop where they welded up the Z bar. Unfortunately the guy managed to melt all of the nylon bushings in the tube. This caused a misalignment of the Z bar & it split again. I ended up using a big washer slipped over the outside of the tube & welded on to reinforce the Z bar until I could get a new one. Eventually had to replace all 4 of the nylon pieces & both of the rubber seals in the tube. Told the PO about it & he went down to the shop & chewed out the guy who did the work for him.