At 2:54 into this video there's a tour of the four Brooke guns from CSS ATLANTA, which are on display at the Washington Navy Yard. Two are 7-inch and two are 6.4-inch. Unlike the exposed bronze guns in another area of the Yard, these guns are in very good condition, having been kept painted most of the time since their capture.
http://www.youtube.com/watch?v=Bs7QTpozkIg
