I don't know if my truck is original or a hybrid? I've never seen another one like it. It's a 1956 GMC with a large back window, a Pontiac engine with a Hydromatic transmission, a period correct Hood Ornament, and the spare tire is mounted under the bed. The only trucks I've seen that have a Hood Ornament have the spare tire on the left side of the bed. Does anyone have information that shows what came standard on the Deluxe model and what the options might have been?
Both the V8 and the HydraMatic were factory options as was the big back window. The hood bird was a dealer installed part I think. The under bed spare goes along with the rear left side full fender . Both that and the side mounted spare are shown in the Master Parts Book, with no reference to what is "standard". Is your truck a short (114") or long (125") wheel base?
There is a list of RPOs in the Master Parts Book, but it does not include RPO numbers nor is there a description matching your big back window or the fender vs. under bed spare. Both type fenders are listed, but no reference to which is the optional fender.