Thanks for all the ideas, guys. I thought about the Mecoa hinges, and looked at some of the Proctor hardware (the measurements are real close to what I need), and got some ideas of what might work. I'm gonna mess around and cobble a prototype together and see how it works. My idea involves making the hinges so I can insert a piece of 4-40 rod from the end of the control surface through the hinges, and then secure the wire. I've seen it somewhere before, but don't remember where.

The other thing I need to consider is, each elevator half on the full scale only has two hinges, and the rudder only has two. I have stiffened the hinge spars with 1/8 hardwood the width of the spar (also gives something for screws to bite in), so I feel that two hinges is enough. What do you all think?