There could never be a complete metal book though. The fact that there is so many peoples ideas. Is the color really purple or blue? It depends on what blue you have seen before and is just a guess in the end. Just like there are so many opinions of the start of wars.
Still I have never read a complete book. Even big publishers can make big mistakes and leave important stuff out. I remember seeing a Rolling Stone Rock history book not list Alice Coopers 1978 "From The Inside". Still there is never going to be a single take on the origin that makes complete sense to everyone.
i've read quite a few books that try to be complete...between them all you can get a good idea, but history is never complete since none of us were there for all of it, and it's colored by the writer
that's part of what makes it fun though!