67 Dart shoulder harness anchor?

I saw the rear shoulder belts pictured in another forum long ago.
I did own one 67 notchback years ago that had the roof anchors from the factory. Maybe it was a late build.
I have aftermarket anchors installed in the roof of my current 67. I wont install the shoulder belts to them until I complete adding the seat back latches though.
It's my belief that the seat backs should have been latched before the shoulder belts were offered.

!!OK!! So you are saying you have effectively proved that not all 67's came with factory anchors? That may be the key to the dilemma.

I don't currently have the factory seats in the car, they are aftermarket generic "race" seats I bought off Craigs. Very comfortable, a beauauch to get in/ out of because of the high thigh rails. They do have seat belt/ shoulder harness through holes. After I saw the 'vert photos I was actually contemplating running one back behind the left side of the rear seat back

"More thinkin required"