OK, so answered a question I had long wanted to know about but was too lazy to go and see. Turns out the spacing on the headrest steel tubes on 1986-later 240 front headrests is the same as the later 240 wagon rear headrests. Sooo, long story short if you’re missing wagon rear headrests in your late 240 wagon, the more easily-obtainable front headrests will slot in. The style is slightly different, and I hesitated to push them all the way in because the front headrests have a notch in the tube that prevents them from easily pulling out of the front seats. I didn’t want to find out that they can be pushed in but never remove from the rear seat backrest. I’ll get out the Dremel tool and cut off the notched portion of the front headrest tubes and try dropping it in when I get around to it. The other thing I don’t know but will check is are the early 240 (iconic headrest shape!) front headrests the same spacing on the tubes as the late ones. Will check and report back.
Front seat headrest from 240 sedan (86-93):
Wagon rear headrests have an extra cross-bar at the bottom of the headrest:
Also fun fact: I fitted 850 (IIRC) front headrests to our 88 240 sedan, so that means they should also fit the rear of the 240 wagons. 850 rear headrest below - they’ve got no vision holes and are padded/covered, if you prefer that look.
240 front seat headrests are usually a real pain to remove. You have to push a plastic retainer clip release tab from the back of the seat, and I find that over time these things must warp or something making them almost impossible to disengage, even if you have the seat trim removed. Whenever I de-trim a seat I always break off the clip to make it possible to remove the headrests without pushing the tab. I suppose they might fly out and kill you if you crash, but they seem to hold in pretty well even with the tab removed.
Finally, the 240 sedan rear headrests are quite different, because they mount in the parcel shelf behind the seat back cushion. You can see the offset shape in the pic below. These headrests also changed in 1986 IIRC and the mounting between the early and late styles differ. Late style sedan rear headrests shown below.
