Just to finally conclude my learning experience.
I couldn't get any of the combinations of internals and externals to work. In hind-site it was obvious.
so I ordered a set of seal kits from Melvyn.
fitted the kit and reassembled the whole system with no further issues.
another option may have been to get new pipes made up to go between the new master and slave cylinders but I didn't have time for that.
Two days later my throttle cable snapped. I couldn't find the right one locally so another call to Melvyn. replacement Fitted within thirty minutes of arrival.
It goes to show that its a lot easier to use the correct parts that try to be clever.
