Hi Jack - looks like when doing the Trim you need to turn off "Project intersections" or else it will find additional splitting points between the flattened projections of the curves and end up slicing things up into several additional smaller pieces near the left-side tip.

Maybe I should fix this up so that if the 2 curves to be trimmed already intersect, it won't look for additional projected intersections...

With that turned off, then the splitting and Network will work to generate the shape that I have attached here as braun_2.zip .

Let me know if that result works for you.

Otherwise to get a more accurate and kind of higher quality result would really require building it up in more strategic pieces at a time which are filleted together, instead of trying to surface the entire object all in one go.

Doing it in more segmented pieces lets you get a lot more control over each individual piece, but it will also require quite a few more shaping curves to be drawn and take quite a bit more time to do.

- Michael