My engine would look shocking next to that!
Are you sure the " mystery wire" goes back onto the coil?
I imagine it wouldn't make any difference where you bolt it onto the engine if it is an earth.

Another question. What is the easiest way to tell if only one cylinder is firing and which is having a bludge?
I ask this because for a mower that is renowned for being smooth, my finger joints feel vibrated numb after a very short time.

Ahh, if only victa had kept producing the thumblatch catcher series, they would be in better shape today!