Possible MSD 6AL failure
I would disconnect the kill switch. If the switch or the wiring has some moisture / condensation problems, (EG) it might have some "leakage" current.
I guess you have read? The destructions at MSD. There are some troubleshooting procedures there
What is it? exactly that you use for a distributor?
You may be able to inexpensively "rig" and emergency ignition. I use a 4 pin HEI module in my car, and built a box to fire up used engines. THEN it occured that it serves as an in -trunk emergency igntion:
Here's the wiring. Important to note the drawing of the Mopar distributor connector. If you use "other than" a Mopar distributor, you may need to reverse them to get proper rotor phase
My emergency system. This is a factory Mopar coil I had, with an HEI inside. Yellow hooks to battery, green is ground, and of course plug wire and the distributor connector
If you use one of these, you need to provide a certain amount of heat sink for the HEI. They have a projection on the bottom, you either need to break it off, or drill a clearance hole in your mount. Mine in the car is screwed directly to the firewall, this one of course is an aluminum box