I'd recommend you to use acrylic paint, it dries faster and is plastic-fiendly, if you don't like the way it turned out you can erase it with nail polish. Oil paint is moer for artistic paint in oleum surfaces. And is the paint supposed to be not complete???
Congratulations! Your making this a contest. This is insane, and has a great chance of winning. But as I tell everyone else, no promises, we have a lot of awesome creations, it will be close...