Cables are run to coil packs on two, three core wires using the same plugs, system was working well untill overheat.
Also found a tiny water leak from an o ring where the heater pipe attaches to the front/top of engine. On long run using motorways could be a water loss.causing overheat after 50+ miles.

Hi All well it's been a long time since last post. Busy with important household jobs.
Back to the none starting issue, since finding the coil wires shorted out, I have now fitted a 2nd hand ECU vehicle fired up but still multiple misfires clyln's 4 and 7. So after checking the coil pack, now fitted behind the battery, one serving 4 and 7 was blown. Fitted two new coil packs. Car now running sweetly . MOT retest this afternoon, failed the first one is an indicator bulb that was working when I checked. And the emissions, Multiple misfires???????. Fingers crossed, not bad for a twenty one year old, will let you know if she passed.

Good result
Good luck with MOT

MOT passed no problem, including MOT joke about an intermittent indicator.
Engine sounds and runs really well. And no water leak or overheating.
Thanks to all for help including Rick the Pic for answering my questions over the phone.

No excuse not to be out and about enjoying it now