Yes... There is a plate that mounts under the package tray and attached with 2 sheet metal screws. The belt itself has a loop sewn on the end and a 3" dogbone goes thru the loop and anchors in the plate and trim bezel.
That's interesting. I had hoped that somehow I could add "stocker style" belts to the (front seats) of the 67, but it obviously has no reinforcement of the roofline