Job done - more or less!
Heater is very effective now. As good as any other heater, if not better, from cars of that era certainly. All linkages doing as they should, and really impressed by the temperature of the air - much, much better than before - imagine, a classic car that has a proper heater, well I never!
Was unable to find the earth connector for the fan switch, tried direct connecting to earth, still no half speed, so have given up on that - full speed works with the lever not connected to earth as it did previously, that will be a job for when the console is out I guess - don't think its doing any harm as is?
No leaks, bulkhead all rustproofed, engine bay cleaned up, fresh coolant and oil and filter, unless I have missed something major, I'm calling job a good un. And time to be driving again at last................what started as a post-Covid recovery boredom 'looksee' was a bit bigger than I thought, but have enjoyed every second of it, thanks in no small part to the advice received here. All other dash electrics functioning as they should, and he started up first turn of the key after all this time. Can hear the timing chain rattle a little bit, but I will turn up the radio until winter time for that.
Many thanks to you all, a beer awaits you should you be passing East Lothian one day. I'm off driving.
Mick