Drop tanks were stored on the exterior of an aircraft and used to carry additional fuel for extra long flights. They were designed to be easily discarded from the aircraft when they became empty or in the event that the aircraft needed less drag and weight, such as being under attack or in an emergency. While drop tanks themselves date back to before the 1940's, they became increasingly popular during World War II.
Material Makeup: Metal
Is it art or is it functional? Well, you get to decide the rest of the story.
Incorporate pieces of the past into your present.