seat belts, window trim, for a 68 dart

Have you considered going to a parts yard and pulling the 3 point belts out of something else ? Your 68 should have shoulder belts so they would be required to pass a safety inspection. Those were seperate belts and buckles from the lap belts without retractores. Metal park tougues at the visors and plastic ones on the front of the seats, just a dang mess really.