Thanks John, no continuity on the yellow/red wire coming from the CDI box to ground when off....... yes when switched on so it's working ok.
Found a service manual online with the correct wiring diagram from the early magneto type ignition (Bay-E download). Gonna separate the ignition from the rest of the wire harness to hopefully narrow down the players in this problem, by giving the cdi and ignition coil their own stand alone ground and eliminating the yellow red kill switch wire I can then see if the CDI, source, pick up and the ignition coils are working...... IF I STILL have no spark then it's only a matter of a couple of obvious parts, IF my spark returns then it's an easy job to one by one plug things back in until the culprit is found. We'll see