For about two years I have pondered over why in some of the SP-D multimers there is a low grayscale area in the center, in some cases looking almost like a star shape, and certainly related to how many arms are in the multimer.  Below is visual trip through image processing a single multimer with 14 individual arms.

Three images also image processed but two diagrams hand drawn of a 12-armed multimer. I will try to figure out a way to verify what I have thought about for all this time…that is, a hollow core SP-D fuzzyball. I don’t see any other way….but the catch 22 is that the shadowed images dont really fit this idea.