Graham, Thanks but I am going the opposite route to TBM in that I am fitting a Rutherford suspension hoop and adjustable shocks and doing away with the original damper set up.
TBM, thanks for the link to your replacement article it is very informative .
When you say that it the moved the axle back a bit why is this and am I understanding you right that the axle moving back has caused the handbrake rods to catch on the fuel tank.
Did you have to replace the axle U bolts for different ones to suit the reduced dimension of the spring.