Here's what I've been able to gather so far. The best pics I could find were out of Detail and Scale, Inc. #69 on the Super Hornet (but they apply to the legacy Hornets as well).
This is the underside looking aft into the open gunbay. The radar electronics tray is upper center and in the retracted (normal) position). This tray would be pulled out allowing clearance for the multi-barrels to drop straight down out of the bay when removing the gun assembly.
This is the open gunbay door showing all the electronics mounted to the inside of the door itself. Not too apparent is the exhaust screens that cover the aft end of the door. Air is forced into the gunbay through the openings on either side of the muzzle opening in front of the windscreen. Down here is where all the exhaust gasses are vented. A large dump-chute for breech gasses can be seen at the aft end of the bay...and very visible even when the gunbay door is closed through those screens.
Left and right views of the gun assembly on the maintenance cradle.
...and a couple of the refueling probe you were also interested in. The one on the left has the forward door still partly open. That would normally be closed except for maintenance when this pic was taken.
Still searching dude, but this should give you a start (or a headache depending on how deep you choose to go).
