Thanks for the input.

Scanned again this afternoon after 5 assorted journeys today totalling about 100 miles.
Nothing has re-appeared except the HVAC Potentiometer one which I've cleared, though it's of minimal significance.

If codes start again or symptoms recur I'll start a new thread in an appropriate section.

must be VERY early .... mine is 2000 with split foglight grills but under steering wheel