Your right about that!
I've built so many of them that things I think are obvious and easy may not be so appearant to someone building it for the first time.
One thing that occurs to me now - I just got asked the question at the field a while ago - is how to do the controll horns and linkages.
You could just use your favorite foamy technique and you'll probably be fine - I have seen them done 4 or 5 different ways succesfully.
However, these surfaces are wider than the normal foamy surface and there are some leverage issues you may run into. I have a couple of ways of doing it that I think work very well.
I'll post some close up pics later.