1966 Voltage Regulators?

Egag, Mouser, Digikey, the smaller electronics supply, houses..........or find an old rheostat. You happen to have an alternator/ generator test set?

18V 3 A Bench Power Supply | MPJA.COM

30V 5A Digital DC Power Supply Variable Adjustable Lab Bench Test Equipment Tool 743828299538 | eBay


BUT BE CAREFUL. This one is not "variable" but rather "selectable".........it has SWITCH POSITIONS

PS-28A | ADJUSTABLE VARIABLE POWER SUPPLY BENCH DC OUTPUT 12V 9V 7.5V 6V 4.5V 3V 744633428489 | eBay

This little kit will give you 1A output which may or may not be enough

Variable Power Supply Kit | Alltronics