Well 1SG. You may find a reverse polarity 12- 5 v solid state reg for the dash on a heat sink , mounted to the column bracket under the dash-the new wires will give it away in an instant. As the electronics techs know , these rev polarity units do not have thier housing bodies referencing so they must be insulated from the chassis of the vehicle. You may be able to swap a reverse polarity solid state regulator with a conventional one of the same specs if you will be swapping to neg groung or just buy one and go back to the old points type that was originally used. I commend you for your wish to use a classic car as a daily driver and hope you have success. I want to say that when I first heard this from other posters on here I was quite taken aback and had thought this was a rediculous quest. Here in NY these autos are garaged and cruised on weekends when the weather is 55-80 degrees. I am suspect of the engine and trans holding up to the tx heat - but to each his own. I would like to warn you of the inherent issues with all the wiring and also the suspension rubber on a 60+ yr old " daily driver". Are your plans to redo these as well?
One other question. Will you be replacing the pertronics with another pertronics of conventional polarity? Or going back to points? There may be a need to replace the rotor if the latter. If so I would hope you may offer up the rev polarity pertronics unit to another member here so they can see how much better a V8 packard runs with one. Advise to replace the resistor rotor with a non resistor type though. ( found out the hard way)