I would trade Alaska and Guam for Kentucky and Illinois and get all six of the Iowas in the war.
As far as the Montana's, while my inner Battleship geek always will love them. They just were not practical compared to getting more Essex class carriers in the war.
Here is a link to a Wikipedia article on “Maximum Battleship” studies done during the WWI period by the Navy at Congressional request:
https://en.wikipedia.org/wiki/Maximum_battleship
More detail on the design effort is provided here:
http://myplace.frontier.com/~wellsbrothers/Battleships/TillmanBB.html#Max
All the designs had their sizes and displacements constrained by the requirement to pass through the Panama Canal. Here is a page with a model of the Tillman IV-2 with 15 18” guns disposed in 5 turrets (2 forward, 3 aft). Model is done in the style of the Iowas but very brutal looking. Definitely a slugger.
http://general-quarters.blogspot.com/2013/07/flashback-friday-tillman-battleships.html
Thank you for posting the model of the Montana. Did you build it?