There is an artist named Andrew Bawidamann who makes pin-up stickers. Here is his website:
http://www.bawidamann.com/gallery/military.html
I bought several of his WW2 stickers, (he has both American and German ones), and plan to use them to decorate the outside of transport cases for tanks. I haven't gotten around to building them yet, but I often like to admire the decorations that are eventually going to go on them.