Ian, thank for that blow-up. I tried but it got granulated or pixelated doing so (of course, I probably don't have any of your sophisticated software tools!
Anyway, you're right, though this feature is one of the hardest to actually spot on these ships, due to the qualities of the preserved imagery.
However, I was not disagree with the feature or how it looks like, I'm going to propose a different way to illustrate it, that's all, and, I am reworking the old drawings, so please don't refer to those right now.
As for my remark about their designation, I'm always aware that what I may know, some others may not, and I rightly suspected you'd know - but then you're a specialist on the USN WW2 vessels!