Hey, @Panhandle Bob!
I'm wondering if your coil is the culprit, because you've gone through 3 modules and still on the same coil? It may have too low resistance in the primary (12 volt) side, thereby making your electronic module work harder and/or croaking.
I hate to make you buy more stuff just to experiment, but we know from @Chappy that you can run a Bosch Blue Coil on it with success and maybe you have the old one still kicking around the Garaje con su Speedster.....
Food for thought....