good eyes in that case! My italians are sadly mostly CP variety and I only have one italy gusty and one italy starflower and one italy glory so I am of no help on the sizing difference but i would not be surprised given the famous quality control that italians are known to have ...
just out of curiosity, in looking at gusty vs starflower I have a pat pend variety vs where the pat pend is removed = to me, a maybe size difference
Is that the case with your two gusty-s? If so, I am thinking it is an indication of different production runs to explain the sizing difference