If you scroll down to the bottom you will find a bunch of 1949 Fords that are decorated for various police, fire dept, and military uses, but could be repainted and perhaps lowered and modified into 1950's era customs with fender skirts, some lakes pipes along the rocker panels, etc.
Unfortunately I looked through 23 pages of vehicles and those 1949 Fords were the only thing I could find in N-scale that would make rods or customs.