They are not mannequins...they are actually cast figures..each one is cast from life from a Marine or civilian of the right height and weight for the era. In the case of the Marines, pilots are pilots, riflemen are riflemen, corpsmen are corpsmen, etc...
It's a four hour process for the casting and then they are painted by hand and each hair is placed in individually. The casting is so detailed that the pores of the skin, and veins in the hands and neck are visible. We have 72 of them, and they cost about $16,000 a piece.
We call the dioramas "environmentals" and are meant to invoke the atmosphere of a specific region - and since they are not "in scale" and contain actual equipment of the era, museums give them a different spin.
Come check them out in person if you can - we open three new galleries from 1775-1918 in Spring, 2010. Or go to our website http://www.usmcmuseum.org
In my real life, I see them every day.
Staff Historian / Visitor Services Chief
National Museum of the Marine Corps