The M/c I removed from my 54 S I has 18/19mm (approx. 3/4") dia. piston and rubbers, with 31/32mm (1 1/4") wheel slave cyl. rubbers, the one that was purchased (M/C that is) has 24mm (approx.) piston and rubbers, so would give a ratio 1.25:1 whereas the M/C removed would give a much better ratio. Can anyone confirm what is the correct size M/C to Wheel cylinders are, Please, Regards Frank.