I found that the lower surface sagged some, too, so I stiffened that area too. 8" x 18" 3-ply layup was applied, with peel ply and polypropolyne sheet to keep anything from sticking. Clamped in place for 24 hrs till cured. Came out nice!
Clamping stiffener layup in place.
View of top of tip with multiple filler coats applied.