[AZKen]

So here is a picture of a truck from a member that is said to be 1961 and it's caption. This is what I said about same factory, different location does not make since. This could be a 1960 as the owner sort of indicates.
Same factory as poster. Kick panel location....and he has the unused pillar holes. This is a %100 nice original truck. Notice the rivet style also.

Caption:
"VIN 1001PN19787A breaks down as 10 = 1000 series, 01 = 115"; wheelbase, P = Pontiac, Michigan assembly plant, N was used for the 1960 & 1961 model years depending on when the truck was sold & titled new."