You can load the backgrounds from the Aircraft Carrier into any graphics package in the .LBM format and spray all the walls with graffiti.
All files in the DG directory can be swapped around. Therefore you can fly an F-16 - frigate - truck etc. by typing:
REN AV-8B AV8B.BAK and then COPY TRUCK AV-8B
Load the game as usual and take off. Now, when you switch to an external view you'll be flying a truc