Turns out the rear valance on the Tbird is in pretty rough shape. No rust but it looks like someone has smashed into a few rocks with it.
When I get the new quarter lined up we're it should be, the valance is about an inch and a half short.

Turns out no one makes an aftermarket peice. And anyone from the states I have talked to dosnt want to take the time to drill it off. They either won't sacrifice the trunk and quarters or want to ship an entire clip (at astronomical costs. )

Anyone know of anywhere I might be able to find a doner car local I could remove one from.
Or at the very least get some measurements so I one work mine back were it should be.