One suggestion, think balsa. I have said it many times. To make big flat plates nothing works better. I have plated every deck with balsa, hull sides - balsa, keel - balsa, bulkheads - balsa. You want to have a flat deck, balsa only warps perpendicular to its grain and easily straightened by adding vertical members, you guessed it, balsa. I make each deck and even the smaller deck house tops by white glueing to balsa. I will soon try this techinique on a carrier. Titanic's decks are every bit as big as most carriers anyways.