<VV> Size of original Clutch head screws for dimmer switch

[vairjer at comcast.net]

Does anyone know the size of driver bit to use for the clutch head screws that mount the dimmer switch on early cars/wagons? I don't have any other need for such a tool, and don't want to buy a whole set of drivers if I can simply get a bit or a driver that is the right size...Thanks for your help. 


Jerry McKenzie