When you observed the clutch disc turning freely when the rear wheels were spun, you have a leverage advantage; put the trans in Neutral, have somebody fully depress the clutch pedal and push on the disc with a screwdriver to see if it turns freely.
Okay we did that and I could not budge the clutch disc. I was able to get a 0.064" feeler gauge between the disc and pressure plate but the disc seemed to be tight against the flywheel. When observing the clutch as the pedal is depressed, I noticed that the disc moves away from the flywheel briefly but then settles down against the flywheel almost immediately.
