Factory rear defrost 67 fastback

I think, guessing here, most if not all 67s, or maybe those ordered to northern climates, got the rear metal window trim with the defrost vent, whether one ordered rear defrost or not.

That way, a dealer could easily install rear defrost by punching a rough hole in the rear panel, covering it with a standard speaker grill, and run the wire up to the dash without the need to disturb the factory harness on the driver's side.

I say 67 as it's an oddball year, and I don't have any direct experience with 68/69 cars.

My 67 has the oval hole in the metal trim, but no rear defrost.