THE STATE OF CALIFORNIA allows collector vehicles to be registered, street-legal, with vintage license plates corresponding to the model year of the vehicle. This is known as the "YOM" (Year of Manufacture)...
CONVERTING YOUR 1955 FORD FROM 6-VOLT POSITIVE GROUND TO 12-VOLT NEGATIVE GROUND There are a number of guides on the internet. They are mostly very good, but in case they don't have something you need, here...