To seal the hinge gap I used some transparent clear plastic film I found in the back of the hobby shop...it was marked as "hinge gap sealer" and sold in two foot by two foot sheets for 98 cents. I thought I would give it a whirl. I bought two packages, so, worst case, I would be out $2. I cut the sealing film to fit the beveled surfaces that were exposed when I opened up the gap by fully deflecting the control surface.

A one inch by eleven (plus a little) inch piece was used on the top and bottom of each elevator gap to make a nicely sealed hinge area. To keep the hinges from crinkling the film I cut small holes where each hinge was so the film would stay folded right down in the crevice as the beveled surfaces came together.

Now I won't have to worry as much about elevator flutter or control effectiveness, it is all taken care of (as long as that sealing film stays stuck).