True but even the fender tag was not a solid date that the car was built on. I believe AlakanTA also said that. It was a guesstimated time as to when the car was built.

Guessing as to what the date on the VIN sticker was without having an original to copy is like throwing a hand grenade blind. You might get some splash damage from the shrapnel but it's very unlikely to nail the exact point ( in this case date) you are aiming for.