I have Indy Pedals and have a cable clutch on my car.

Anyone found a solution using the above and mating it to a Hydraulic Cylinder to feed the Hydraulic clutch slave cylinder of the bike?

I don't want to really alter the pedal arrangement (difficult to get down in there now it's finished)

Might be worth looking at the master cylinder on Rover 600 and 800 (also 75) it uses a master cylinder that fits entirely inside the pedal area --- single pin mount on bulkhead.