Ed, I do believe it's the other way around. A waist-high railing on 1/700 scale would reach the shoulders of a 1/800-scale sailor - right?
It might be worth buying one or two sets of photo-etched parts to see if some of them could be used, with or without modification. (One possibility that comes to mind: maybe 1/700 four-bar railing could be trimmed down to 1/800 three-bar railing. And maybe such things as radar screens and deck-edge safety nets would look acceptable without modification.)
I haven't bought any of those old Otaki/Arii 1/800 carriers, but as I understand it they're pretty nice little kits - though hard to find nowadays. If memory serves (as it frequently doesn't these days), there was an article about a model of the Midway, based on one of those kits in FSM a few years back. My vague recollection is that the model, which had quite a bit of additional work in it beyond the contents of the box, was pretty impressive.
Good luck.
Youth, talent, hard work, and enthusiasm are no match for old age and treachery.