That's a race I would have enjoyed...it's written down in speedway folklore.
My first visit to Hyde Road (1984) I remember well a race involving Hans Nielsen, PC & Chris Morton. Hans made the gate and tried to cover as much of the track as possible as PC & Mort were buzzing around his rear wheel and they both eventually passed him...one on the outside the other the inside and there was nothing that Hans could do about it!
Going back to the 1973 PC & Mich encounter I recall that PC was operating both the clutch and throttle on the same right (?) handlebar...quite a feat!