As far I can tell, my '57 is all original drive train, interior, and most sheet metal, that switch looks like mine, a 3 wire switch. I mounted single bulb (1157) tail lights along with the fender mounted front turn signals. I wired two DPDT relays and the 2 wire turn signal flasher can. I'll try to find my hand drawn wire diagram.
1957 Chevrolet 5700 LCF 283 SM420 2 speed rear, 1955 IH 300U T/A, 1978 Corvette 350 auto, 1978 Yamaha DT175, 1999 Harley Davidson Softail Fat Boy
| 
