thanks Ron,

your diagram and pics of the tach really helped me! so new tach is in, but alas running rough and not idling. So now i checked each lead for spark, changed out button and cap - actually back to the original items, and still running rough with no idling unless i give her gas in which she still sputters to a stop. Replaced condenser with a new one and shes purring like a kitten; i think all the sparks flying around spoilt it, not sure of the diagram i couldnt explain root cause if i tried, but anyhow a happy ending thanks to the fabulous technical help and the parts this time provided by Nick T in michigan,

once again thanks so much all!

Rob