I just finished skimming through this book, Gundam Scratch Build Manual, that originally came out in 2003. I have to say that it is a very good book for those who want to learn how to modify and scratch build mobile suits. When I say scratch build I mean building it from the ground up with minimum existing model kit parts. The ball cap joints for the arms and legs is something you'll probably want to get from off the shelf parts though.
The book is more than a hundred pages and will teach you how to modify an existing kit using styrene (sheets & rods) as well as with poly putty. It will also show you how to create parts from the ground up using putty, casted blocks of putty, styrene sheets. There's also a segment that will teach you how to create parts using resin and by vacuum forming styrene sheets.
Oh, and before I forget, the book is in Japanese so its a bit difficult for people who can't read Japanese to understand it. If there is one reason why Japanese modelers seem to be light years ahead of their world wide counterparts when it comes to modifying and building kits, its because of the availability of books like these. Just another case of experience building up on experience, which equates to modelers learning tried and tested techniques then innovating on from there their own techniques.
I checked at some online hobby stores and I found out that the book is long sold out at HobbyLink Japan and Hobby Search
