Today our audio guys and I visited the Tesla Forum exhibition "Nikola Tesla Exhibit" which has working (mostly) machines of Tesla's. See link here for the event information. Both Mark and Trent had a go at recording sounds and playing with an active Tesla Coil. We hope to use these recordings as reference and possibly clean up the sounds to actual use in game.
Links to videos are below:

Trent Curtis (Foley Design) at the Tesla Forum exhibition.

Mark Kram (Tracks Design) at the Tesla Forum exhibition.