Thanks MBDoc, I will trace the actuator - But does the Cruise control work if the ABS is inoperative? (as I have occasional erratic behaviour, I guess it does).

A mini-update on progress:

I checked the rear axle ABS sensor and it shows open circuit, so either the sensor is dead or the cable is damaged. Guess I'll be spending some time under the car tonight.

The stalling seems to be worse when the engine is warm. I find the worst part of the journey is leaving the freeway after a 25mile straight run, I struggle to keep it alive (I drop it in Neutral and rev for a few seconds before it stays running). Once it is ticking over it is smooth and stable at 650rpm and pulls away well. Could this be the carbon block solenoid valve? [Edit - Not sure about this as I deliberately braked at the first island and it stalled when cold]

Will post back when I have checked out your suggestion.

Thanks