The late '30s & early '40s series used a coil with a locking cap and armored cable protecting the ignition wire from the key switch. I guess to prevent hot-wiring the ignition. Called "Electrolock" or something. Took a "special" tool to remove the cap to get access to the primary wire.
If you need to replace the ignition switch, wire, or both, it's awkward, with the armored cable in the way.
Sadly, that I know of, nobody makes similar replacements.
Awesome cache of tools! Wonder how many are original GM issued tools?!
-Michael