The dark area here in a fuzzy ball (not my AFM image, someone elses) shows a consistent 6-8 nm dark center…. between the N terminus peaks.  Both arms (as best as I was able to stretch them from the CRD across the fuzzyball (which may not be at all accurate, and i think is NOT accurate but used for now) the center is vacant.  or at least it has a valley in the LUT tables that is nearly as low as the valley before peak 1, 2, and 3 begin on the left and right halves of the molecule.  I think it is more likely that two trimers bend into a U shape and are connected somehow side to side.  I will continue to measure the arms as separate entities.

On the surface this might seem like a thankless task but i could be a valuable lesson in how collectins link together to make multimers.  Side to side links at the N termini in SP-A and MBP and other c-type lectins makes it very likely, more likely in fact because of images like that below, than any other arrangement.