So, that was easier than I was expecting.
New Cam Cover arrived this morning, fitted it, ran it, checked/cleared Fault Codes, all sorted.
It had also failed for the Stabilitrak Warning Message and Light.
Removed the front ABS Sensors, R/H one had a bit of Brake Dust on it, cleaned both.
Poked a thin strip of Solvent-soaked Cloth down the holes and spun the Hub to try and clean the Sensor Ring.
That fault cleared and didn't come back, happy days.
Took it down for the retest, passed.