I can't find that issue. I was taking the mags to work back then and I think they got borrowed. I'm positive about the vin being on the engine and I have talked to other people that really know the documentation business and they swear to it. Of course you can find car owners and dealers that will fight this because their cars don't have the numbers. Others, like you Salmon, will look for the truth. I first ran into this anomoly when trying to document an original 67 GTO. Years later, I found that the 1967 Firebirds were later stamped too.
Jim