After digging through the garage a little, the originals were more of a sliding toggle switch.

http://www.oldchevytrucks.biz/catalog4/00023.htm

http://www.classicautopartsgroup.co...&action=detail&item=P3946-2485-A

New ones are nothing like the originals. The new ones are toggles. Mine mounted about 2" left of the vent handle underneath the dash, should be a large hole with 2 small holes for the screws on either side of it. Hope that helps.

Jeff

My 1953 Chevrolet
1947.1 Gallery
1972 C-10 1/2 Ton & 1972 C-30 1 Ton