I was looking online the other night and found a few copys of frank de haas's book "single shot Idea" book, before I go one I looked into what books my dad has and as it turned out he had a new copy that he got free from some club a while back, I looked through it and its amazing the info that is in it. Anyways I want to pick up his book on bolt action rifles, I see the 3rd edition is alot cheaper than the 4th. cant tell what info is left out of the 3rd. I'm going to be working on a few mauser actions here soon and I want to learn some more things on various actions. also how does the "mauser work shop manual" look? is it worth while to somebody building one from the action up or is it more of a care and maintainance book.?