I think I have it right that the steel trigger wheel is fixed with screws from the back of the Millers Mule Crank pulley.
Correct.
Looking at the photo Marcus, if you don't want to move the pickup could you get a small idler on the bolt holding the PS bracket? That looks to be the ideal location to move the belt run up a little.
It would be perfect Stuart, however the belt for the PS pump gets in the way unfortunately, and finding a small idler for that size bolt would be difficult I feel. I was contemplating whether the M6 for the cambelt cover could be used for a small idler but would need substantial bracketry to go with it to take the strain.
I spent some time today working on a solution, and looks like it should do the job. I've turned it over by hand and all belts seem to run clear of each other.
I've cut the bracket top down to as close as I dare...
then when taking the alternator out, managed to knock the solid pipe for the PS around to give more adjustment for the alternator, and brought the alternator out slightly which results in it just clearing the bracket / sensor by a mm or so...