Was not aware these existed: https://www.ebay.com/itm/NOS-1967-6...+Sport&hash=item3672ff41de:g:VMIAAOSwV8lfCXeX
That's a real thing that was in the TSBs. GM would send big bags of them to the dealer. That's a crazy price though. That seller always has desirable senders for GM cars. He's a flipper, been doing it for many years.