Those formers aren't glued down in that pic, are they? Also, in real aircraft, to make formers stick to compound surfaces, the binding agent is a very thick, think, "thick peanut butter, no nuts" as gooped on around an inch thick and wide. This holds the composite surface to the formers, and takes up any difference in shape. Think compound curve saucer, straight edged top of former. Put some longitudinal formers to make the framework even on both sides. You will have a very strong saucer section. Looking really good.