Black 72 Dart Retracting Seat Belt Unit

I need a retracting seat belt unit, I either need the passenger side black or both of them that emerald green type color, because my black drivers side still works. I need the parts mounted to the floor that retract the seat belts in a 1972 Dart or that will fit. I'm not sure what they are called. Can't post a picture because I can't get a photo online to copy the url.

If there is a way to rebuild the units, please let me know as that would probably be the easiest.