I don't want to hijack Bob's thread with the color photo at the New Jersey assembly plant.
Were the script beds painted body color when they were installed at the factory? There is a red truck and a green truck that you can see in the photo with flatbeds installed and the beds are painted body color. I have not seen very many script beds in original state, but as I recall all the ones that I have seen have been red or what is left of the paint is red. Maybe they were all off of red trucks?
I have a magazine advertisement from '48-'50 and it shows an F4-F6 134" WB with a script bed and it is painted yellow like the cab.

 

The script bed I just got was painted black over the original yellow. It came off a 48, so was the body color Chrome Yellow, I assume. It matched the yellow truck in F$Bob's picture.