67 FB Barracuda seat release missing piece?

Well... 67 buckets didn't have latches on the seat backs. Those appeared in 68 model, mandated along with the addition of shoulder belts. Apparently you will need parts from 68 or 69 model seat(s).
Any loose seat parts are extremely difficult to find. Complete and correct 67 buckets would be easier, ordering the correct skins and all. Good luck