That seat belt light was used on 1970 B body cars as well, when you had the C15 deluxe seat belt package. As previously mentioned, it gave you the 71 style seatbelts.
My 70 Charger R/T SE sublime dealer demo car had the deluxe seatbelt package with dash light.
March 18 SPD.
Greg
Wards Classic Car Radio Repair Specializing in restoration and sales of Mopar A B E body radios We can restore YOUR radio usually in less than 7 days Visit our NEW website.. http://www.wardsclassiccarradiorepair.comgregward@mchsi.comphone 256-852-0955