Hi nonstoprc, you are on the right track. For several years, I have mounted my stab adjusters the same way. The best way I've found is to mount (with 2 screws) the stab adjuster to a small peice of 1/8 inch lite ply that has been shaped to match the INSIDE of the airfoil of the stab. After removing enough foam to allow the ply plate/assembly to fit flush with the rib root you then glue the ply plate to the foam and the inside of the upper and lower 1/16 balsa sheeting. This way you can be assured the lite ply plate is glued to something more secure than just foam. I then use either 1/8 inch balsa or 1/8 lite ply to cover the foam root rib surface, leaving a small opening for the aluminum adjuster rod and finish off with two small access holes (top and bottom) to the adjusters. Also let me add, that your measurements, openings and holes, etc on each stab half need to be a mirror image of each other for alignment purposes when you reach the point of actually mounting the stab sleeve/tube and adjuster rod in the fuse. Hopefully, my directions make sense. If not PM me and I'll try to provide more info to help you find what will work best for you. Regards, Everette