On my first RV6 I built up a dam of epoxy on one inner edge of the fairing and then had a flat to flat surface to deal with. I then used double sided VHB tape from 3M to close the edge. At annual all that has to be done is slide a razor knife along the seam to open the fairing and then just reseal with another piece of tape. This is a very easy, clean method to close those trailing edges and not have to bother with piano hinge and wire.