I'd go 3.5 stars if I could.
Interesting subject matter. The book starts with an historical overview, and then has chapters on individual makers/models.
There is a lot of good information here, but...
The book needs a proofreader, especially for the first chapter. Some sentences/paragraphs are completely nonsensical, like machine translations.
It's obvious there's no overall guidance to the organization or style of it; it's just a collection of peoples' work, most likely amateur enthusiasts. This isn't necessarily criticism, just observation.
The pictures were a serious disappointment. There aren't enough of them, they're very small, and most look like they were copied on a poorly adjusted copier.
I'm good with the idea of gathering assorted (free) sources on a central theme, but the production quality should be better. The book costs as much as those whose authors must be paid, so there is little excuse for slapping it together this way.
It's similar to MP3 downloads or e-books, with no production or shipping costs, costing more than CDs or books.
joe