Paul,
I tried the ASCOM driver last night with PEMPRO.
Worked great!
Polar aligned the mount within a few arcsecs of North on both axes.
Then ran a check to see what the periodic error was like.:

Needless to say, I'm quite happy with that!
Next step nopw will be to see how to train the PEC on the mount - must have a read of the manual tonight.
Michael.