In this photo gallery I have included several types of BOSCH switches that can be use in the twin-plug ignition of a 914-6 GT race cars, here is a dash photo of the #40 Sonauto 914-6 GT https://pbase.com/image/25692332. These switches are NOT all the same and I will try and point out some of the differences between them.

The correct BOSCH ignition switches used by the Porsche factory in the 914-6 GT race cars have two distinct attributes; (1) The finish of the switch plastic button is a "smooth shiny finish", and uses "Push-On/Quick-Disconnect" type connectors https://pbase.com/9146gt/image/136566771, not the "screw-type" https://pbase.com/9146gt/image/136566746 wire connectors. Both type of switches function the same way, however only one is the correct ignition switch for the 914-6 GT. You can clearly see the differences in these photo galleries.

Take a look at the newer type switches https://pbase.com/9146gt/image/24004144 they are not correct. These newer replacement switches have a "texture/wrinkle finish" of the plastic knob and the switch itself uses "screw-type" connectors.

By the way, several other early Porsche race cars including the 911 RSR used the same switch as the 914-6 GT https://pbase.com/9146gt/image/23962390 - https://pbase.com/9146gt/image/89596746