I have resolved the case! People today are not aware that the tailgate goes to a specified vehicle. They are actually convinced that it is a back rest for a bench seat. So if you do a search for tailgate bench seats, your almost more likely to find the tailgate than you would be searching for the tailgate.
https://www.ebay.com/itm/1958-1966-C...4AAOSwaYVbL9nH
https://www.ebay.com/itm/1958-1966-C...gAAOSwKAJbL90N
https://www.ebay.com/itm/WILL-SHIP-R...sAAOSwa3BaDzpU