It has been a while since I built the last one and I sold my last one as well to make room. If I recall the flaps and airlerons are about 3 " deep and run from just outside of the fuse to the last rib by the tip.. I know the flap was a bit shorter than the airleron but I must have used a common rib to make the split. I recall I just traced a profile of the common ribs, then drew on some half inch balsa to cap where I made the cuts. Then I cut the rib and used it as a templete to mark the other ribs. The flap had an angle cut with fowler type hinges. The servo has to to be strong because you need a long arm to make the flaps go down as close to 90 degrees as possilbe. The rudder was only increased by about 1 inch over all as it is pretty big now. but more helps when you are doing a harrier a foot of the ground, lol. Funny thing is we never heard of 3D in those days, I guess we kinda created it, lol.
Regards,
Randy