Am in need, went to the parts store and was amazed at how high tech these things have gotten - And expensive.
Basic models were about $45, all the way up to $200 with models with digital readouts and tach functions ect.

I don't use one enough to justify even the $40, so I dug this relic out of a bin in my garage, and am looking to rehab it.
As you can see, there are 2 lose wires, I am guessing this was for some kind of clip that clips onto the spark wire ?