It is now April 4th, 2019. I am sad to say that I have seen this nice movie only once, and it was probably in the spring of 2010. So approximately nine years have passed, and I do not have exact recollections concerning the plot of this film. In any case, if you want to know the plot, Wikipedia has an article that provides it.
I just remember I Quattro dell' Apocalisse as a visually beautiful, well-acted spaghetti western. The DVD version that I have (Anchor Bay release, The Spaghetti Western Collection) is absolutely uncut, with all the violence shown. I still remember that some gory close-ups have been taken from another movie print, and that fact is noticeable because the picture quality is slightly different in those moments. I am glad that Anchor Bay folks have hunted down the missing material and restored it into its proper place.
Today I noticed that Blue Underground has released a Four of the Apocalypse blu-ray, and I hope it is uncensored. If you can make sure that it indeed is, then I could recommend buying it. I Quattro dell' Apocalisse is a very good spaghetti western, and the first collaboration of Fulci and his cameraman Sergio Salvati.