I just recently bought a 72 comet I don't see any seat belt buckles. I was wondering whether the buckles were connected to the floor or to the seat. I can't see anywhere on the bucket seat where they could connect, and I don't know whether there was new carpet put down over top of the studs, or holes for the studs.
The buckle portion of the belt attaches to floor near the rocker panel. The insert portion attaches next to the tranny tunnel. The shoulder belt was an odd arrangement that buckled into the outboard side of the buckle and could be hooked up on the side of the headliner above the doorframe. Ultimately, the elastic on the shoulder belt wears out, and if you are tall, the buckle tends to smack you in the head if you aren't using it. Probably Ford's way of reminding you to use your shoulder belt.