This is my piece de resistance!
Toggle balls with the cord looped through the holes and cable tied,not knotted.This was so I could move them easily as and when The cord settled in beyond its prestretched condition.
I concepted that;to rotate the skeg I would push ,with my toes ,one or the other toggle ball.I got a shock when it just siezed up....This was before I glued the deck on but.
I figured that I needed to do the opposite to the the other toggle to release the tension on the " back run" so allowing the forward run to move the skeg.Nice feature I thought.A skeg that locks it' self.
Fortunately the skeg only has to rotate 75 mm worth of cord travel and my feet don't need to do too much dancing to operate it.

I haven't got an image of the thing sticking out of the hull yet but the skeg is a very good way of changing the characteristics of the boat,instantly and also by degree with half deployment being usefull as well.
cheers from Paul .nz