Hello Saxier,
I've used bodies to try and approximate my particle by simple shapes. It fits a hollow sphere okay, but in principle I think it would fit a hollow semi-sphere much better (or maybe even a hollow semisphere atop a short hollow cylinder). Is it possible to define your own simple geometric bodies and make bodies refine that to your experimental data?
Bodies - Definition of shapes
custom shapes
BODIES does not allow to define custom shapes. I've heard that the program SASfit (from PSI/BAM) allows that but I haven't used it.