Kutscha...you are looking at the BOTTOM FUSELAGE of the Me109.
The fuselage was skinned in 2 halves...both halves joined at the top and at the bottom (what you are referring to in the photo). No overlapping was done on the top and bottom seam, however they overlapped on all sides. Section 3 overlapped 2 and 4...section 5 overlapped 4 and 6, etc.
Please reference Georges photo...
Mike