Not sure if you ever got the cable for your sofa slide, but after both of ours broke recently, I contacted PC/USA & spoke with Dave Ponsler. He said they had just gotten in an order of the cables & he shipped me two immediately. They cost about $35 each. Although I had to be a bit of a contortionist to get them installed, they replaced the originals perfectly & both sofa slides now work, hopefully for many years to come.
Bruce