then the problem is with the clutch plate being seized to the flywheel.
there are several ways of free that off
the easiest is the way you've already done it once.
the way i'd do it, get the landy moving, by starting it in gear. Hold the clutch pedal down, and floor it. once you got a little bit of speed up, lift off totally, then floor it again, then lift off again. that should free it off.
another way to do it needs 3 feet. get the motor moving again and spam all 3 pedals.
if neither of those work, its either engine or gearbox out
Ian