Mike,
Granted. But, I am almost finished with my 1943 New Jersey; I used the old Tom's Modelworks conversion set. That was a straightforward conversion because Tom's included all the resin parts necessary. Unfortunately, they don't make that set anymore. Yankee Modelworks had an Iowa conversion set, but I do not know whether that was the open bridge as she was built or the closed bridge of 1945.
The Korean War Wisconsin should also be a simple conversion that basically involves the removal of all 20mm AA guns and most of the 40mm Bofors, then scratchbuild a more intricate mainmast, remove the catapults and their supporting structures. I'm sure that there are other details to change in the basic Missouri kit, but I haven't looked at that one fully yet.
I also haven't looked fully at adapting either the Missouri or New Jersy kit into the 1968 New Jersey; it will probably be an exercise in kitbashing!
With the release of the new kit of the 1991 Missouri, I can now build both the New Jersey as recommissioned in 1984, and any of the other Iowa's upon their decommissioning.
Anyway, it is a great time time to model the Iowa class, as it is a great time to be a ship modeller in general!
Bill