There is a wire at the starter solenoid small terminal marked with an "I".  That wire ultimately connects to the positive terminal of the coil.  Its purpose is to provide 12 volts to the coil for starting.  The  resistor is not powered when the ignition switch is in the "start" position.  Somewhere in the  pertronix installation that wire did not get reconnected. or the starter solenoid is not sending the 12 volts to the coil.

John - "The Hoosier Hurricane"

I installed what I think was the Pertronix Ignitor on my 56 Victoria about 50,000 miles ago and have enjoyed not having. to reach way back in the engine bay to change points and condenser. I run a stock 292 with a later 450 cfm Holley 4 barrel and hand choke.. I kept the original coil and external resistor. I have enjoyed the set up other than hard starts on cold mornings. It seems odd to me that the motor more often than not, will fire only after I release the key from the start position to the on position. And if it doesn't fire off the vacuum wipers will jump in place occasionally. Shouldn't the motor fire in the start position? .