Richard,
At a quick count, my current boat is the eleventh.
Non of these have ever had, despite much effort, a clew outhaul which could be used to adjust the sail, when led forward to the gooseneck or to the cockpit.
The problem is that the friction at the clew overcomes all efforts to adjust whilst sailing; you can usually slacken the foot tension, but not tighten it.
Therefore, questionable whether replacing the internal lines is worth the trouble.
Frank
Frank Marsden