3157xxxxxx - decodes as
31 - Belvedere /6
5 - 1965
7 - St. Louis, MO assembly plant
xxxxxx - VIN sequence number
The tags were pre-stamped "from the back" with the last 8 digits of the VIN#, so there would only be one VIN# 57xxxxxx. They were later stamped with the first 2 digits "from the front" denoting the "CAR LINE".
Does the fender tag SO# match the core support stamping?
Title "typo" or one of the tags swapped from another car?
(Brand New?) or 45 years later the first two digits aren't always clear.
Here's a
W1 1965 tag