Thanks for the reply.
"I don't see a ground wire from 5V supply to ULN" - I thought I'd read that ground should be between the 8266 and the ULN2003 boards and in this case not directly to the power board? I'm sure I've tried it straight to the power board with no avail too, along with those 8 pins you've mentioned. I will retry if that's the correct way though.
I grabbed that as example code online but I can try changing it to 5 or 6 as per your comment, will do that tomorrow and report back. Oddly it does start rotating if I connect the ULN power pin directly to the VV pin on the ESP board, although with very little speed and torque so I know the components are at least working.