Just trying to get a common size for SP-D multimers and dodecamers. These are data using molecule diameter, a single AFM image from Hartshorn et al.
You can see that these images are just slightly smaller than the means found for Arroyo et al. Whether prep, or differences in the actual SP-D are responsible is a question.

Some species just cannot be determined others are covered up, and so it is an estimate, i understand that. For trimers smallest diameter was used, for hexamers as well, for all other multimers at least half the CRD had to be on the rim of the circle to determine the diameter.