it is also most probably fairly important that I chuck this in:
To balance the shaft I will 1/2 fill the smaller dia shaft with sand and then seal up the shaft so that there is no water ingress and no chance of the setup rusting.
I also think that it is a good idea to put a bicycle inner tube over the slip fiting to stop water and grit getting into it.
I will most likely use 2 1/2" x 1/4" wall tube for the outer and 2" x 3/16 or 1/4" wall for the shorter inner tube.
I will also most probably use tom woods uni's for all uni's in the double cardon and the other end of the shaft if I can get them to fit a Toyota.