I ask because I am really interested in alternate history settings involving world war 1
I second this...I would be fascinated to see how others see the potential outcomes :)
I don't know if it'll match your requirements, but I know "Leviathan" is an alternate First World War story. Now, I can't tell you much as I've never read it, but it's got something to do with Britain using bio-engineered animals to fight and the Germans using mechs.
The boardgame Tannenhäuser is about WWI continuing for a lot longer. I guess nobody has won yet, but it is still a different outcome. Visually the game is quite impressive.