OK thanks for that Tony, I'll come over when I get a chance.
If there's any doubt i will re-set the sub-frame and test drive but i'm positive the positioning is not the reason for the pull simply because the brake action is a compressive force geometrically so acting on the camber (vertical) and toe (lateral) whereas the sub-frame movement is longitudinal.
If the brakes are perfectly balanced, is there any other reason you might know of that would cause this? It feels kind of weird as when I apply the brakes quite firmly, the steering wheel doesn't move but the car moves to the right and I have to turn the wheel slightly to the left to straighten the car. Thanks for responding Tony.