The USN was finding spare 16" barrels and rounds tucked away in warehouses years after the last Iowa class was decommed.
Even today there are people (naval officers not "enthusiasts" like us) who avocate bringing back large caliber guns in the professional journals.
Marines especially like this idea.
It's not finding barrels and rounds, it's the machines that are used to check and fix them when they are found. The USN very very quietly got rid of that gear a few years back, and the stocks of un-rifled barrels withing the bast year. Also if the Battleship enthusiests were really dedicated they would have pushed for the engines and engineering equipment from the Sacramentos be saved - which it wasn't.
The large caliber guns are not coming back, and the sooner that people realize this the sooner the debate can move on to other more productive topics - like what the USN is going to keep as budgets shrink over the next couple of decades.