Yes, it's true - she's back on the road! And the problem? Well it wasn't spark plugs (though I did replace half, and will do the other half when I don't have a thunderstorm to deal with). It wasn't fuel starvation - in the conventional sense of the word.
What it was turned out to be a lack of fuel (nearly empty tank) and a serious amount of gunk in selfsame tank! Yes, those are my finger-marks, having dragged through the debris to haul some out and see what it was. There were sticks, sand, mud and other bits, quite a collection.
I undid the plug below the tank, drained and scooped it all out, rinsed it with clean petrol and filled it up - and she started first shot!
YAY! We're back on the road! Took a quick turn around a couple of blocks and she's running well.
The only issue now is idling. It's set too low and I had to go on choke to keep her alive. But that's not something too difficult to sort out.
Here's to travels! At last... :-)