In '70 Dusters the shoulder belts were attached and stored with clips on the headliner over the side windows...I believe that was the first year for shoulder belts and that arrangement lasted a couple of years IIRC.
Then I'm very confused. I just looked at a 73 Duster, and there is no sign of them. No headliner marks, no mounting location, and the lap belt buckles don't have the "pin" for the sash belt. (I remember those from my grandmother's car.)
Well...the mounts have to be there. Guess I might be ebay shopping. (At least that will be easier to ship than a car...)
