in my experience with quite a few 55-59 trucks from different plants the gas tanks weren't painted, they were galvanized when made and installed after interior paint - heaters were supplied by Harrison, already painted a hammertone gray lighter than the charcoal
just remembered there's a
low mile original in the gallery you could refer to, doesn't seem to have a heater, and looks like the gas tank may have been interior color, although it's a Canadian truck
Bill
