First ime I have run across ones like this. Came from a 71 Skylark no ac, 4door with vent windows. The rear drivers side door had no armrest, and a more decorative door handle. the ashtray-in-the-armrest was on the rear pass. side. The dash has no vent openings, and the instrument cluster has none either.
Probably not much call for that dash as never used on upper end Skylark or GS. I had a mint blue one and gave it away.