Here is what I did. Both of the 1/2 inch beams were glued in place as was all of the filler strips between the rib cap strips, before the ailerons are cut free. When locating the 1/2 inch false spars, make sure you have the proper gap between them. If the gap is not the right size for your piano hinge size and location, the aileron trailing edge will not line up with the wing. Once the ailerons were finished with all bracing in place, I cut the ailerons free.
Next sand the face of the 1/2 inch false spars so that the cut off cap strips are flush with the flat surface. I did not countersink the holes, but used washer head screws instead. There was no problem with clearance. Watch the location of the mounting holes on the aileron. There is not much wood on the back of the aileron false spar due to the shape of the aileron.
Regards, Rick Schreiber