'70 Challenger rear end vin stamping?

[71-LS6]

For what it's worth; Many years ago a very knowledgeable friend of mine showed me all of the partial VIN stampings on a car (70 Challenger) that we were gutting. He showed me the following locations
1) radiator core support
2) the cowl stamping
3) the driver's side deck lid drip edge.
When you opened the trunk and pushed the weather stripping over some, you could clearly make out a partial VIN derivative. I don't know what the build date, sequence, or plant of origin was, but I did see a number. From what I remember, all the big Mopar gurus say this stamping never existed, and that one car was the only time I've ever seen it.