FYI, There is a Coastal Artillery history group in California, since there are two museums coastal batteries still left (one is near San Francisco - the Precideo and other other in Los Angeles - Osgood/Farley Battery). The one in Los Angeles had 14" guns. They filmed scenes from Tora Tora Tora and Dragnet, the movie, there). I think they have a website, so if you contact them they may help you.
Camp Pendleton still have bunkers from the Coastal Artillery Railroad gun and the Breakers Apartments, formerly the Hilton Hotel, in Long Beach still has the observation bunker in the building tower.