Okay, at the moment a friend and I are in the midst of doing a reversal on history: We are making the Guillliman Hersey, where all the old loyalist chapters are the ones who go renegade and the traitors stay by the side of the Emperor. We are trying to stay true to the Primarchs' personalities (Though tweaking a few elements of their background so as a few of them aren't definitely going to turn (Angron comes to mind, as does Mortarion). All the major points will be there: Istvaan, the Council of Nimbaea, the Warrior Lodge on Davin, the Siege of Earth, all with their own twists. And trust me, we are going to try to be as clever and original with this as possible: It isn't going to be a straight switch for every loyalist chapter's obvious counterpart. In the end, we are going to try to do some IA style articles on them and name it all "Codex Obscuras: The Guilliman Hersey".
Problem here is that I was going to look at the old summaries of the Horus Hersey books, but the problem is that the old site is gone. We were going to use those to pick out key events. Can someone repost the old summaries of the books?