Thanks to RichardL again, I copied his schematic for the wiring of the IACV.
The default settings in the Emerald software do not use IACV, so you need to select it as an option from the Idle Control screen. I first chose manual control from the menu and used the Page Up key to increase the setting to see if the value was working. As it got to 30% the car started to idle cleanly - wonderful.
Next I switched it into mapped and uploaded the settings again. Idle from start is now smooth, ticking over at about 1000rpm. I let the car warm and adjusted the fan control to force it to turn on. No problem either.
Lovely day so a great excuse to get a couple of photos of the car so far....
Another super day, and to finish off I drove the car back into the garage!! First movement under its own power