seat belt advise needed for 65 coupe

hello there, da ole boy down hea in south ga needs some advise on installing BACK seat belts in my newly aquired 65 coupe. it has them in front. i am a new member so i suspect i may be in the wrong forum. ain't very good at understanding these newfangeled puters. if anyone could help, i would appreciate it. a diagrahm displaying mounting positions for bolts as well as suggested sources would be very helpful. thanks and have a great day.