Rather than replace the worn out steering head bearings with new loose ball bearings as per the factory, I decided to go spend the extra cash and go with tapered roller bearings. What this image also shows is the area below the washer below and the bearing is now 'space' where I removed 'material' from the triple clamp. This is because the CB750 clamp is slighly thicker here and does not allow the stem to protrude through the upper bearing far enough to allow the lock nut to screw on (confused - read on?). I then pushed the bearing all the way to the bottom of the stem!
This image shows the lock nut in place and tightened up! And now everything works properly, including the steering stops which are in the same place.
And now the top triple clamp goes in place with its lock nut....Job done.....Now just have to make the wheel fit the forks!