I do not think there was ever any thought of an internal gun on the A2F-1/A-6 Intruder, even in early designs.
This poor photo of an unpainted early A2F, likely the first protoype, does show 3 round objects on the inner leading edge of the port wing, so guess we can't call you crazy, but I do not think they are gun ports.
http://www.aerofiles.com/grum-a2proto.jpgAnd this source shows the prototype flew for 8 hours before being painted. After the paint job, the "ports" no longer show up. Perhaps the were just some type of marking or something to do with the production process such as a rivet pattern?
http://www.cradleofaviation.org/history ... n_a-6.htmlNo painted YAF or A-6 seems to show anything there. A photo of the mockup shows nothing there.