Thanks very much Dave,just the info I was after..
I was lucky enough to find a new shim amongst my bits and pieces... measures .018" ... should be OK..
I was thinking .... at some stage in the Bikes' life,the Engine sprocket had come loose.I wonder if that was the cause of the shim being damaged so ..
Anyways ... we have a new shim,new bearings and a new crankshaft assembly to go in ... that should keep the Goldie contented for a while.
All the best mate ..