the Heater Delete option?
As promised, here are some pictures of my right-side 'heater delete' vent box. Don't mean to side-track this from the OP question but it's sort of relevant.
I have the little door handle, just forgot to show it in these pics. The foam rubber seal gasket is wasted.
The seller sent me everything including the hangers. When it arrived at my door, the door was still attached but just barely. The second I opened it, it fell off. Probably hadn't been moved in decades.
Back side.
Side view. I'm not sure what the angled cutout is for but if I had to guess it would be a steering column bracket or something. I'm not sure if the '68 Hemi Darts or 'Cudas had these reliefs, might be unique to the Australian cars.
Outer side. The part number is stamped on both sides.
Bottom side with the brass rivets. The shape is actually kind of complex.
Part number and 'old' Mopar logo. Cool!