Great motor, you're a lucky man!
With regard to the clutch, a method I was advised to use on my Triumph 2500TC that hadn't moved in 20 years was this:
Jack up the rear end of the car and support securely!
Start the car in gear, you may need a higher one.
push in the clutch
accelerate to reasonable speed
grow a third leg or alternatively heel toe the brake and accelerator
basically the rear brakes should slow the wheels enough that the torque of the engine will free the clutch.
Try not to cook the brakes if it doesn't go instantly
Slip the clutch a bit to clean the surfaces and all should be good
When I did mine the speedo was hitting about 60-70mph in 4th when it shifted!