Disagree, if it is in the Salesman data Book that is Genuine GM and for the purposes of originality (judging if you take it to that length) is accepted as a "factory" option. These options appear with a factory part number not a vendor number. Parts are referred to in factory literature, manuals, and brochures.
Section 1
C. General Policy
The objective of AACA judging is to evaluate an antique vehicle which has been restored to the same state as when the dealer received the vehicle from the factory. Any feature, option, or accessory shown in the original factory catalog, sales literature or company directives for the model year of the vehicle, will be accepted for judging. .....
Hmmmmm, now add to the fact that most of our trucks came with no factory window sticker (not required until 1958) or documentation it makes it pretty tricky. But if I have a period correct accessory or optional item that matches the factory literature for the purposes of originality as outlined above I think I am covered.
