There will be no need whatsoever to have the charging system in operation for a short run. Disconnect the wires from the generator and regulator, and simply run temporary wiring to the ignition system. A well-charged battery will get the engine started and run it for several hours on nothing but battery power. I'd suggest running a new 12 volt coil and battery if all you intend to do is run the engine long enough to load the vehicle on a trailer. Use a ballast resistor between the battery and the coil if you choose, or just let the points carry the full voltage if you're only planning to run the engine for a few minutes.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!