Ok.
Tests have been performed.
They turned up no voltage on either the source or the pulse coil. (lighting being left out of this for now)
The multimeter was wired in parallel with an adapter that was thrown together with a couple of bullet connectors and clips.
I did not realize that the plug cap was not installed until after I had tested it and had the generator off... Although I think it should have earthed through the black wire on the generator plate?

1. Should the pulse coil generate voltage without a functional source coil?
    The pulse coil looks ok. And measures ok.
     
    But, it is not generating anything when kicked over.

2. I think my source coil has been repaired at some point, possibly multiple times. It looks a bit crispy but measures within spec on a meter.
     
     
This one probably needs replacement. I am fairly certain this is not normal, the tape covers a similar join like that aborted repair(?) below.
I think I need something like this.
As to why it worked for 150 miles and now doesn't, despite the fact it was not disturbed, is anyones guess, unless it is not this.

The rotor seems in good condition, as does the woodruff key, it is solid with no slop at all.
It looks like something might have been dragging slightly at some point, but as to what it was. Again, anyones guess.
 

CDI ignition.  Green/white wire is usually lighting coil. It turns into a white one at the loom multi plug. Source coil is brown wire.

Usually.......

Yes sorcy thing certainly looks dodgy but strange you can't get 'some' AC voltage with the resistance you have. Not sure of the colors but guessing at brown so test lead to brown & other to ground.
If it's got two wires coming out of it then one lead to each.
Similar with pulse/trigger coil but on a low reading as only looking for 5 or 10.
Gotta have the flywheel on of course & not overly tight, just nipped up on the nut.
I'll re-guess sorce could be a black/red wire but whatever exits it.
Pulser is usualy/always a white/red.
That's connecting at the mag loom with 'that' loom unplugged from the main loom. Not further up in the loom.

Short update.
New source coil fitted.
Still no voltage measured.
However it seems to have spark now.
This suggests that it was a fried source coil.
As well as an error in voltage measurement technique.
Its going back together to see if it will run shortly.