Riveted top and bottom skins to both D cells & spars (L&R). TIP, I had some difficulty finding a bucking bar that would fit between the skins when doing the bottom skin with th top alreadyt attached, I found that the special purpose bucking bar that you use for the HS fits perfectly between the spar flanges, and you lay it flat, put some pressure with a finger against it to snug it up to the rivet head, and it works fantastic, just start at one end and keep scooting it along as you go.
