I`m on holiday right now, so I can`t work on the model, however I have a completely new model in my head, I know how to model the head and the rear to look much better. I`ll try to draw some drafts later and scan them, but don`t expect me to start working on it until August. Sorry
BTW, the neck will have superstructure, I`ve removed the fairy tale castle roof.
About the Executor: yup, the shields were down, I think there`s a mission in XWAlliance to take down the shield generators, and in SW3 we could see that the command ship had shutters, so I guess imperial ships also had them. However, the AWing hit so hard it completely destroyed the bridge of the otherwise heavily damaged ship. It would`ve been destroyed w/o that AWing