Original question: I served on the Gearing class DD USS
Brinkley Bass (DD-887) in 1970. She was in FRAM-1 condition at that time. In 1973 she was transferred to the Argentine Navy as CT
Mariz e Barros (D-26). She was decommissioned in 1997 and sunk as a target on December 19, 2000.
From the photos here
http://www.ussbrinkleybassdd887.com/...otogallery.htm it looks like not much was changed in Arentinian service.
Armor question: All battleships had armor to resist heavy shells. Most cruisers had armor thick enough to let them fight other cruisers. Some carriers had some armor, but destroyers never used armor; it wasn't worth it, and they weren't meant to stand up to heavier ships.