Here are some details from photos I took aboard the USS North Carolina last summer. They show a couple different types of stanchions. As I recall, most of the rail was threaded with cable, not chain, though some sections did use chain.
Maybe there's an old salt in the crowd who can shed some light on this. It might be that chain was used on deck sections where the rail needed to be dropped for action or other purposes.
NC-4-87: Three types of rail visible here: welded rail on the gun tub in the foreground, cable-only on the mid-deck, and cable and netting on the main deck. Note the diagonal bracing on the stanchion at the end of this section of rail. I believe (not sure) there's a ladder just to the left of the photo, leading down from the mid-deck. I wonder if the netting is for the benefit of landlubbers and their rugrats, or if it was used when the ship was in service. It's a long way to the water.
NC-4-144: Rail abeam the #2 Main battery. I wonder if the odd-looking, hefty stanchions here are meant to support some kind of transfer apparatus for loading shells and charges from shore to ship.
NC-4-148: Rail adjacent to a Bofors gun tub on the main deck. The object on the left is the gun director. Here they use chain.
NC-4-148a: Just aft of NC-04-148; that's the same Bofors gun director to the right and a block on the left. We're back to cable.
Looks as though you have your work cut out for you. My suggestion would be to plan a visit to the Missouri (at Pearl Harbor) or one of her sister ships--the Iowa, at San Francisco, or the Wisconsin

mrgreen

at Norfolk, VA. If you go to Norfolk, I highly recommend a side trip to Wilmington, NC to visit the USS North Carolina. The Iowa and Wisconsin are still in USN registry and their public tours are deck tours only. The NC is decommissioned and the tour takes you through nearly all of the ship. We were there last August. There's no AC aboard the ship, so it was warm below decks, but well-ventilated.
It's a fascinating trip, well worth the time.
Cheers,
--David