I guess it could be from a later year. But all the seat cover colors matched the 64. they could have been added later to the seat back possibly. Wish I could speak to the original owner. Oh Well.... Heck I they could be off anything then.
If anyone has a pic of a 66 or 67 let me know. I would kinda like to know what I have. I dont have the head rest. all I have is the brackets that mounted to the back of the seat. They are re-chromed but now im not gonna use.
Heres the seat in my 64 Nova. This was originally out of a 66 4 dr. I don't know anything about brackets on the back of the seat. ( on the outside of the seat?) The factory option head rests load in from the top of the seat. The recieving mount hardware is inside the seat frame on mine.
Show us what you're talking about.