Best product for treating old vinyl

A friend of mine used to use Gojo on the dash pad of his 70 Roadrunner. It sat outside all the time, and the dash pad never busted. He would rub it down with Gojo, and let it sit on it for a few hours, and then wipe it off and use Armor All. I don't know if that would work the same way on a vinyl top, but you could maybe try it on 1 A pillar and see if it softens it up. Bruce always said it was the amount of lanolin in the Gojo that kept the dash pad soft.