I dont mean to sound unconvinced but i fail to see the differance from having the servo in the top slot arm facing down or having the servo in the bottom slot arm facing up as the arm will cross over the cable in both cases. If you look at this photo you will see my point:
http://www.edge540t.com/imagepages4/P1260017.html
now if I place the servo in the lower position arm facing up the linkage will be more lined up than it is in the photo. I may be way off base here but mstroh3961 seems to see my point. I figured i would put the question out there before i go cutting into the plane.