The wings, externally, aren't too remarkable. There art two very large stress panels under each wing that screw on/off outboard of the wheel wells but all all skins are butt joined (not overlapped). The fuselage is where it gets interesting. The 108 and 109 each have, behind the cockpit, seven skins each side about the width of a traditional "frame bay" on a normal, semi-monocoque style design. On the 108, the forward edge of each skin is joggled (so an overlapping adjacent skin won't protrude above) and then flanged to act as an integral frame and the adjacent skin is overlapped onto this joggled edge. These flanges were then notched for longitudinal stringers and the end result is no separate frames. On the 109 the manufacturing process was simplified in that every other skin is joggled and flanged on both forward and aft edges leaving the remaining alternating skins simply cut to shape. This presents as fuselage skins that alternate between slightly narrower (the underlying joggled/flanged skins) and slightly wider (flat) skins. The end result was flush, especially if the narrow area of the joggle transition was filled.