parking light socket and wire

I have a 1952 Ford Vic. Positive ground 6 Volt. I just bought a replacement parking lamp wire and socket. The early Ford dealer said that his wire was correct for my car. However, it was advertised for FORDS 1952-59? I thought Ford went to negative ground and 12 volts in 1955? I am concerned that this socket and wire is not correct for my car? What do you think?

 

Wire does not care about voltage. one wire goes to the power other wire goes to ground.