Updating this thread. I found the two plastic circlips that permit the headrest to tilt had broken. I discarded the lower (flat) portion and left the portion the encircles the rod. Using ordinary, metal, perforated pipe strap I fashioned a new loop. If done properly, you will not even need to drill holes, just use the existing ones in the metal strap. Bolt it back in and tighten down and it works good as new.
