The surprising thing - for all of them - remains that their locations appear to be so different on different ships - even within the same type of fit. You'd expect that all the Essexes would have a similar arrangement of internal spaces and equipment - so the access to them would have to be in about the same places - and the same would go for storage of their required tools/fittings, as well.
But it just ocurred to me that the deck-edge was where these arrangements of equipment probably varied the most - particularly the deck-edge guns you mentioned - and particularly with the addition of starboard-side 5" sponsons on the SCB-27s (but also the great variation in 20mms, as well) - this might explain much of the mismatches so far observed on the starboard sides.
I know it sounds geeky, but this topic is becoming more and more interesting to me - not least because these openings, peeking out in key places, really give an Essex carrier the look of an Essex-class carrier.
So, thanks for the input, Donny!
Oh - and one more thing: what the h*ll are you doing up at four in the morning?!!! Go back to SLEEP!