50 bucks is NOT a lot when you look at the effort this guy put into
this utterly unique document, and how few copies will be sold to a
highly specialized audience. He interviewed dozens of principles. He
tears down EVERY one of the blue-white tube vintage models from his
own collection, including the legendary C22. Make no mistake about
this, it is a MASSIVE effort, and he will never be remotely repaid for
the effort, other than for love of the hobby.