I ended up fixing the foot pedal which was evading me all weekend, thanks to these diagrams from Joe. I do credit him and a few other people (Tammi!) on the vintage sewing machine forum for enabling me 2 years ago.
Turns out my 1, 2, and 3 wires were in the wrong order within the prong. Only took 1 zap to find out (I forgot to unplug the cord when I was testing the order).
No copyright info on these images – but I wm still posting or I will lose them.