Thanks for the reply, Paul.
I think I have sucked up every picture that google has to offer on the subject and I have Nigel Watson`s book.
A good friend with access to a 3D printer has done a set of wheels, idlers and sprockets for me, which has saved a lot of problems from rearing their ugly head.
There is a MAFVA branch near me so I will see if a copy of 47/2 is available.
I do believe I am in a position to start a build ,fingers crossed.
Malc