TC
Check out
www.pegasusautoracing.com
They have all of the British threads to AN fittings so you can adapt the Smith gauges to Aeroquip fittings....
I'd try the smaller slave cylinder and then consider a stop for the pedal....I think Tom K. was saying to do something to the master cyl shaft to restrict the movement for the slave cylinder.....
It's fun when you start this kind of sorting out and balance of the car....
BTW did you check the bump steer??? don't know how the Kirkhams do it or if they pay much attention to that kind of detail.
Enjoy
Morris