a real low ID number on the vin would be an indication it was early production
"Also notice how the running board contours to fit under the back of the cab."
which the factory did not do on any year - and the outside edge contour doesn't appear to match well - there's just way too much "custom fitting" for that to have been factory, even for a one-off proposal, prototype, or "quick, fake something because the real boards aren't ready yet"
if that was factory you have a totally unique truck, now you need to find the proof positive it wasn't some later add-on, even by a dealer "finishing" a truck shipped "incomplete" or later adding a bed to one shipped as a cab and chassis, which would have had short boards
Bill
