2020-04-10: First step was to flip the wing over once again. It is easier to mount the lower winglet «upside down».
I started this step by removing foam to make the plug fit inside.
Then I bondoed a couple of wood pieces on the outside of the winglet to ensure the lower winglet is parallell to the upper winglet, then I had to adjust the inside of the lower winglet to fit the junction between the wing and winglet.
I chose to glass the inside first – and used two plies instead of just one, as several other have done as well. I made a fairing between the wing and lower winglet using flox, not micro.
2020-04-12: Sanded the plug to blend in with the winglet and glassed the outside with 2 plies of BID. The part forward of the winglet is for the navigation lights and has to be adapted to the particular light I will purchase.