One thing that you should consider is, there might not have been any "stretch" taken place in the cables - something else might be causing this. If I were you, I'd leave the cable alone and take the pads out, fully retract the pistons, clean up everything, refit pads, use brake pedal to drive pistons back out, and then and only then operate the handbrake quite a few times to let the mechanism re-adjust. Also, consider fitting external lever return springs - I suggest original shape Alhambra as the source car.
Edit, by all means remove the trim and have a look at the cable equaliser when the handbrake is fully "on" - if it is just stretch then the yoke should be sitting across the car - if it is "canted to one side" then things definitely need cleaning up.