Getting close to the final sand. I keep finding low spots and filling them with epoxy and fibre filler to bring them up. Afterwards requires some sanding to get them close. The final sand will use a 4' long section of aluminum hand railing. Since it will be a general area sand, I won't be able to hold the vacuum to capture the majority of dust so I'm waiting for a warm day to bring the wing outside to do that. Created the access panel for the great retraction box. While I was at it, I cut out and prepped the panel for the RH wing too. While looking at the underside near the wheel well, I decided that I should make a skin stiffener similar to what was done on the topside. The skin on the underside in that area won't be as stiff as the topside due to the hole for the wheel and the rest of the landing gear. As such, some additional skin stiffening should be added. Maybe it was there in the original, maybe it wasn't. It wasn't shown in the drawings but I'm adding it anyway. It won't hurt. Lastly, I spent some time reviewing AC 43.13-1B - Acceptable Methods, Techniques, and Practices - Aircraft Inspection and Repair, and looking at the fabric covering on the aileron. From what I can see, the aileron and likely the wing were not covered as per AC 43-13. The rib stitching was too far apart and technically, there should have been a layer of fabric tape over the seam at the front edge of the aileron. Similarly, there should have been fabric tape over the seam at the leading edge of the wing. I suspect there wasn't.