Deburred ribs from right aileron and cleaned off markings in preparation for priming.
Measured, marked and cutout opening for the aileron trim tab in the left aileron. The drawing specifies a 538mm width but that dimension will not fit between the two center ribs without interference so I reduced my opeing width to 533mm. Will also have to shorten the corresponding trim tab width to 530mm.
11/23/13 Update: Found - after clecoing inboard ribs in place - that I could widen the trim tab opening to 537mm without interfering with ribs, so am now only 1mm short of drawing spec.