Manufacturing the base attachment plate proved to be a real challenge. Cutting out and bendig each metal part took hours of pure handwork. In order to get all three main bolt holes in line I had to build a template for the welding job.
One major step forward. The first three parts are assembled and provisionaly attached to the spars. Once the fin is positioned at its exact position on the fuselage the holes for the spar attachment bolts will be drilled up to 10(!) mm.