All of the 64, 65, 66 and 67 Skylark and GS 2dr. HT and convertibles use them as well as the 66 and 67 Special Deluxe 2dr. HT and convertibles.
In addition, the front armrests in the 66 and 67 4 dr. HT Skylarks use them (they also fit the rear doors, but the rears are supposed to have an ash-tray mounted in them).
The 2 door post (sedan) models and the 4dr. sedan models all use a different style armrest all together.
I am not familiar enough with the Skylark sportwagons to know which type of armrest they use. Ted--are you out there?!