Early 2 litre disc brake conversion

[David C]

I'm pleased to say Graeme Payne has found some 406 hubs for me to go with the 406 stub axles I already had so I have the front setup ready for discs on the 400.

My next challenge is to sort the rear brakes. as 1" wheel cylinders can't be found I am considering getting larger ones sleeved. It should be straightforward to turn down the actuator but the challenge lies with the spreader for the 1" cup.
I know I could fit a proportioning valve but that's far too easy...

I have a new vacuum tank but it's missing the one way valve that the hose clips onto. Any help tracking down something suitable would be welcome.