I am having a mental block about a balloon I am trying to model. It is one of these barrage balloons used during WW2, mostly in the UK. At least this is the British standard model.

The body is fairly easy, but I cannot find a way to model the fins properly, with their three overlapping sections and soft lines. loft, sweep etc create kinks in the sharp turn near the tip. I tried to do a boolean union of three shapes, but the base (where it meets the body of the balloon) should be one single smooth area.

Any suggestions ? Thank sin advance.

Jean-Paul