I did re-check the wiring. Black to ground (pot body), red to switch as per the instructions and in-line with the existing humbucker wiring. I thought about reversing the wiring to the "wrong" way but didn't, maybe I will give that a try first.
When you mix and match different brands of pickups you can get often phase issues when they're combined, so reversing the hot and ground on the bridge pup would be a good first step.
Bingo! Thanks WeirdBits all sorted now. Reversed the polarity, had to extend one wire, now all is working fine. Just wish I had ignored the instructions and logic in the first place.
No need to spend any more money as she sounds just like I wanted the bridge and bridge/middle to sound.