It is my understanding that the Iowas had to be decommsioned because their hulls were thinning due to electrolysis. Building a new BB with modern gunnery with be very expensive but modern 16inch guns could I am told hit targets 100 miles away. Something to think about.
In any event, I would not think it would be too difficult, or expensive, to design and implement some form of cathodic protection system to slow/halt the electrolytic deterioration of ships’ hulls.