There was an article in the Restorer a couple of years back. Basically, take a piece of thin plywood, screw it to a cabinet hinge, then screw the cabinet hinge to the header. The tension that normally holds the cabinet door closed holds the visor against the headliner.
Alternatively, some of the vendors sell the hinge that was used in the ‘31s, but you need to add in a wood rail in the roof to attach them to. Ok if your headliner is off, difficult if not.