Saving Old Seagulls

As you might know, I'm new into Seagulling, but I do have 30-odd years of 50 - 250cc motorbike engines experience.

If your multimeter is an analogue one (with needle) you'd have to short the leads and calibrate to "zero" (end of scale).
With digital meters short the leads as well, and take notice ...

Three questions:

1) Have you got a spark and if so what colour is it? Blue at the very rare time there is one.
2) What reading are you getting between the HT contact and earth? The multimeter doesn't move no matter what scale it's set at.
3) Which version of the ignition is this - Villiers or ...

I'm having difficulty getting a decent spark from my 40 plus. I've cleaned the points and set them to 20 thou, replaced the spark plug and HT lead, and done the 5 minute spin thing. Still I can get it to start. I am slightly confused with a continuity check. If I put one lead of my multi tester on ...