Ran across this link on the net and thought it was interesting. It's a short "Timeline" of the development of the airbrush.
http://www.wgn.net/~panther/airbrush2_history_timeline.htm
I thought it was interesting that the airbrush has been around since 1879 and was first called a "paint distributer"
This link: http://www.wgn.net/~panther/ is the root of his site and has a lot of pictures and other information about old airbrushes. The owner says he has 200+ airbrushes. I think that even beats you, Mike