The only times I've seen coils leak is when the ignition is left on, and the points are closed. That'll cause them to overheat, sometimes to the point of exploding.

Which leads me to wonder about the wiring you did with the push-button.

It's probably just a fluke and your coil has given up the ghost, but, As currently wired, what do you do to turn the car off? And is there a chance that the coil is getting electric even when the car is off?

As for coil options.. I really don't think it matters. Were it me, I'd carefully remove the whole thing as a unit, and replace the ignition switch with a cheap aftermarket guy (you can keep or ditch the pushbutton.. personally, I'd keep it), and.. well... a Bosch blue, fine. Or anything from a 240 or whatever... Really doesn't matter, in my opinion.

Those Bosch blue guys sure do look cool though!

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-Matt I ♥ my ♂