The Fordson Tractor Pages Forum

Here's another view, which shows the other side of the coil.

Strange it should go wrong after 60 odd years of reliable service.

Interesting read
https://mossmotoring.com/lab-coat-lessons/

I agree, but there are so many mysteries like that!
Superb find John! Now we know how to fix them, the only hurdle is getting diethyl ether! Now to try for luck on ebay and get a gauge for Billy (not very much there at the moment). I would still prefer a complete one but it's not essential.
Sandy