The ship is based on this image: https://commons.wikimedia.org/wiki/File:Yamato_battleship_under_construction.jpg#/media/File:Yamato_battleship_under_construction.jpg

the artist forgot Mamiya ;-;

Nekurumi said:

The ship is based on this image: https://commons.wikimedia.org/wiki/File:Yamato_battleship_under_construction.jpg#/media/File:Yamato_battleship_under_construction.jpg

So that explains Houshou's flight deck!

Nekurumi said:

The ship is based on this image: https://commons.wikimedia.org/wiki/File:Yamato_battleship_under_construction.jpg#/media/File:Yamato_battleship_under_construction.jpg

Oh..i recalled immediately about that pic, that's when I truly understood the HUGENESS of those 18 in and them turrets (the front face of the turret remains the only piece of armor impenetrable by any shell at any range except point blank)