Hi Finema - I'd probably try modeling one section and then using Transform > Array > Circular to repeat that section around to make the full shape.

To start with I'd array a line and rotate it by 1/2 turn to build the "base wedge" that you then want to build the section inside of, see attached 3DM file for a quick starting example, which looks like this:



Hope this gives you an idea for how to get started - you'd need to add more details like trimming the top of this shape from the right-side view, and then modeling a second piece rotated at a 1/2 step interval for the next section.

- Michael