There were 67 orders of only 1 headrest. I've read that the reason for no headrest at passengers seat was about a ladies big hair-do.
Those headrests used in 67 a-body were transferred or imported from b-body and found mostly in convertibles, not to say they weren't ordered, 1 or both, in others. Anyway... That's why they are so different from headrests made for a-bodies.
There is a 69 B'cuda in this forums "for sale" listings that has a complete set of 67 buckets including those headrests. That could be a way to get all the hardware that goes inside and outside the 67 seatbacks. That or the b-body forum.
Pre 68 buckets don't have safety latches on the seatbacks so they don't belong in any vehicle that has shoulder belts. So twice wrong in that 69.
Good luck
