Marty, I personally have never seen them, but I haven't seen them all. I have had about ten or less 68 head rest cars over the years and none of them had the wedges. Also, none of the other head rest cars I have seen had them. Did the owner have any documentation proving Originality, like Ford Engineering numbers? How did you judge them? Dock Points or Give Points?
From what I understand, 68 Cougar XR7 had a longer Trim shaft then Mustang because the XR7 Seat Padding was 'Taller' then Mustang. Could these wedges have been added by the owner to fit some XR7 Trim Bezels?