Pic Needed Shoulder Belt Mounting Location

My car came with them, but when we did the crazy roof swap on my car (which included frame and all), the new roof section had come off of a 67 or 68 model Dart so it didn't have the mounting bosses. Is there a place that sells the individual seat belts? If I can find a pair of black belts to replace the ones that came in my new belt set, then I can live without the shoulder belts.