Ahoy maties,
I served on Nassau from 11/81 - 2/85 (EM3). I sent a bunch of pics to the web-dude from my time on board. Some pics of the equator crossing in the I-O (MARG '82) and pics of other ships taken (while at sea) and a series of pics of the IOWA first berthing at Norfolk.
I remember the 5" on the FWD PORT CORNER and on the AFT STBD CORNER (of course I could be wrong as to which side of the boat they were on but I"m possitive that we had 2)...as far as the missile launcher? We had 2 PHALANX systems installed; 1 was above/behind the missile launcher and the other was on top of the Island. (Portsmouth...'83?)