Spherical Jigsaw Puzzle

I was thinking about what a spherical jigsaw puzzle would be like (e.g. like the wikipedia logo); in fact, someone here on thingiverse already made one; but one where the pieces form a thin shell. I was thinking about what happens if you make the pieces thick. If you do, you cannot just cut the sphere along the edges of each piece with a virtual knife pointing at the center of the sphere, because you wouldn't be able to get the pieces in and out.
So then I realized that if you cut the pieces out in such a way that you can actually get them in and out of the puzzle, then the result is a jigsaw puzzle which requires a specific order to put together, which I thought was kind of cool, and made the puzzle more interesting. Here is the result of that musing, along with the python (Jupyter notebook) code.

Printing these pieces is not particularly easy. I find that when I print something with a round surface, if it's downward, it doesn't produce a good printed surface. What worked bes