I'm working on a 70 coupe and it looks like the car was originally equipped with 3 point belts. However, one of the previous owners CUT the shoulder belt...is there a place where I can just buy the shoulder belt? The lap belt has a slot for the shoulder belt to attach to, so I think all I need is the shoulder belt. I'm not sure how it's supposed to work with the retractor and everything...any help is much appreciated!