Cool stuff, but for some reason the Navy Blue on the last drawing is different than the Navy Blue on its predecessor.

Impressive piece of work, David! The main battery is huge!

Manufacturing new 18 inch shells would be easier and quicker then designing and manufacturing new 16 inch triple turrets

How much main gun ammunition are you really going to use post 1944? I very much doubt its worth the cost of new turrets and guns.....

Anyway love the ships and the detail going into them.

It would most likely have happened ca 1941, so quite a bit.

IMHO, by 1943 a more likely (and definitely more achievable) secondary armament refit would replace the 6/47 triples with 5/38 twins, and replace the eight 5/25 open mounts with six to eight (not sure amidships) single 5/38 pedestal mounts, probably Mk 12. This would mean you wouldn't need to rip up O-2 for 5/38 handling rooms (which would instead replace the newly opened trunks of the 6/47), you could mostly re-use the 5/25 ammo handling I suspect, and you'd have the awe-inspiring total of 11-12 5/38 barrels on either beam. You'd also recover a lot of stability margin; I'm a little bit skeptical that the current refit would work without bulging. Not nearly as awesome for surface warfare, but by 1943 I think the 5/38 would win out.

Of course, it's your design

(you have a slight copy-paste error on the top view, one of the 40mm tubs above the aftermost starboard 6/47)