What doofus would remove a VIN plate during restoration? Anything that casts doubt on provenance can lower the value of an antique item, sometimes to zero.
It's a very common scheme to own a car that is junk or wrecked, so you steal another car of the same model and swap the VIN plate onto it to claim it was your car all along. Has that ever happened during the 63 year history of that VIN plate? Hard to say now. The rivets that were holding it on in 2017 may have been obviously bogus, thus a desire-- by the restorer Mr. Ramirez, who naturally claims the car was not stolen, but has not been cleared in the investigation-- to get rid of them.