I finally got round to fixing this, I had power all the way to the dash, I pulled the dash apart and there were some marks on the tracks from where the multiplug provides the power to the PCB, checkign these out with a multimeter showed that the main +12v feed into the dash must have a break, I experimented by soldering a small wire across the points and bingo! the dash worked again, I now have my speedo and Revcounter back in action, how chuffed am i?
I'll see if I can upload the piccy.

Many thanks for the help and colour wiring diagram.

Magshttp://upload4.postimage.org/1885082/cctboard.jpg