Regarding the maintop: Going by the historical trend exemplified by the Big Five, the Lexingtons probably would have ended up with an integrated AA gallery replacing the middle level, rather than the "birdbath" tub on top he way the Nevadas and Pennsylvanias did.
Regarding the capstans and hawse pipes: I learned this after it was too late for me to fix it: The refit in which Maryland and Colorado got their bulges also included the deletion of the center anchor, including the capstan and scrape plates, and a plate being welded over the hawse hole in the deck. The bow notch remained.
Speaking of the hull differences... it could be an option for when a kit is ordered: 1941 version with bulged hull and 1.1 quads (like Maryland), or original unbulged hull with 3"/50 singles (like California).
Regarding the turret 3 catapult:
Like FFG-7 mentioned, they wouldn't be centered; and comparing against the Nevada and Pennsylvania classes, as the turrets get larger they tended to leave less of the catapult hanging over the back - but in all cases, the overhang at the back of the turret just barely clears the mainmast (obviously to minimize how much of the catapult overhangs the gun barrels). Looking at the Big Five in photos, they've got the catapult hanging about halfway out the length of the gun barrels, but mounted quite off-center (even requiring braces off the side of the turret to support it), and canted off to the side to stay just barely clear of the guns elevating. Bit of a rough photo of the California, but shows what I mean pretty well:
https://www.navsource.org/archives/01/014432a.jpgWith Lexington's turrets being a bit longer that the TN and CO classes, and with only two guns per turret, it
should be even easier to do something similar - unless the mainmast cage is notably closer to the back of the turret. But even then, the longer turret ought to be able to absorb more of that catapult length and thus not need as much overhang toward the mainmast.
Looking at the Lexington renderings, I see an enclosed platform that would definitely be in the way (California, in the photo above, has a similar platform but it's above the catapult. Hers was always that high, but I expect they'd have moved Lexington's up, or deleted/modified it to clear a catapult. But also, these enclosed platforms seem to have all been removed by 1941.) I also see a vertical pipe of some sort between the turret and the mainmast that would even more quickly block the catapult. What is this element, and is it something that could be removed or trunked out of the way? Given the scouting role of a battlecruiser squadron, it's inconceivable the USN wouldn't have crammed two catapults on them somehow, and if it took trunking an incinerator exhaust (if, for example, that's what it is) off to the side I'm sure they would have. And the external rangefinder on the turret roof would have to go, of course (could be move to turret 2. California had one there in 1941, for example.)
- Sean F.