I have the same questions about the swing keel, the cable and rope.
I was going to attach a thin tracer string at the bitter end of the keel line, pull in through. I would then record the measurements on the new line and cable; attach the tracer string to the cable and pull it toward the keel, once through, attached the cable to the keel. cut-off the excessive line in the cockpit.
My concerns are maintenance on the blocks at the various 90's which the cable goes through?
Greg