1968 Chevelle Buckets - Converting to Headrests?

[L78M22Rag]

My 1968 elkie originally came with headrests but the original seats are trashed (covered with crush velvet) and the headrests are long gone. My buddy sold me a mint original set of 1968 black Chevelle buckets that don't need recovering, but you guessed it... no headrests.

Can someone tell me whether these seats can be converted to accept headrests, and what would that involve?

I noticed in another thread that 1968's had the rotating lock for height adjustment. Does that mean the headrest bars are different?

Oh, and... yes I'm on the lookout for a set of headrests if anyone has a nice set for sale.