Exactly what happened to me at about 60,000 miles on the clock back in 1991. The pivot pin had worn the metal down in the mating recess of the clutch fork.
It had worn away so much there was no strength left in it and the ball of the pivot pin went through the clutch fork. Hence the clutch pedal went all the way down then became locked solid when returning back up.
The silver lining was that it prompted my V8 implant after buying S&S conversion kit in a box. (I never got the box though)
Unless someone knows better it an engine / gearbox removal job. Its not that difficult, it just takes time if you have the space and resources and it'll give you a chance to look at the state of the rest of the clutch / engine bay at the same time.
Adam
TR7 V8 DHC Jaguar Solent Blue. 9.35cr Range Rover V8, Holley 390cfm, JWR Dual Port, 214 Cam, Lumention, Tubular Manifolds, S/S Single Pipe Exh, 3.08 Rear, 200lb Spax & PolyBushes all round, Anti- Dive, Strut-Top Roller Bearings, Capri Vented Discs & Calipers, Braided Hoses, 4 Speed Rear Cylinders, Uprated Master Cylinder & Servo, AT 14" 5 Spokes or Maestro Turbo 15" Alloys, Cruise Lights, S/S Heater Pipes, Replacement Fuel Tank. No Door Stickers. Mine since July 1986, V8 from 1991 courtesy of S&S V8 conversion and big brake kits.