Before you go nuts removing transmissions and slave cylinders, try filling up the clutch master and pump the peddle, you might not even need to bleed the clutch system, its an old car and I bet no one ever serviced or changed the fluid, it doesn't hold much fluid and probably evaporated, if filling the master works but still seems a little spongy then just bleed the system as you would with brakes, the bleeder is right on the slave. Use dot 3 brake fluid.