The car is a '94 with 147K miles. The Check Engine light never came on. According to the tech it would likely not have come on until the engine began to really miss - which started the day I got it in to the shop. So, I was probably just in time.
When we removed the black friction tape wrap of the wiring harness, literally all the insulation was crumbling or disintegrating.
At the coil ends, the insulation under the harness had completely vanished.