My '36 half-ton demo, I purchased it in the '80s+- from a seller's picture ad in EFV8.
I hadn't heard of demos, but viewing the '36 Ford-green, dentless, obviously rare-optioned pics, I realized this one was special. The only reason I purchased.
Owning the truck, I researched the demo history, per Ford;, i.e., use it as a demo with its attention-getting bright yellow cab, hood. After the year of demo'g, have your dealer paint shop paint over the yellow w/a Ford truck-color paint and black fenders. Then it will sell.
hmmm. this truck was green w/black fenders. I scratched one scratch, low, back of cab by the running board six inches in, between the cab & box.. Yellow! This was a demo. The doors had a vague worn-off/buffed-off two-foot diameter apparently company logo of some kind. (sold it to buy a '33 coupe when one became available ( the '36 pickup is still being enjoyed on California roads 150 mi east of here.
Thank you for 'listening'.