Well, NEW JERSEY during her 1968-69 commission never removed them - they were there in place during her second mothball period (1957-67), her third commission (06/68-12/69), her next mothball period again (12/69-11/82), her fourth commission (12/82-02/91), her subsequent mothball period and final museum position (03/91-present).It is a matter that they were removable for stowage elsewhere when not being used. At sea and not loading ammo, they likely were stowed away.
I do have photos of IOWA/WISCONSIN at Philadelphia in mothballs (1950s-1980s) where those davits were missing - so, it's probably true that during WWII and The Korean War periods and later mothballing during which those items were stowed elsewhere (probably below decks).

