Here's the way it looked like before:
Here's how it looked like in the middle of the process. Decent, not stellar. I ripped up the flooring (sticky plasticky tiles) so that when I attach the new flooring it'll rest flat. It's okay to have some overhang to trim off later. The bottom will be covered with flooring, so I don't really have to worry about that overlap. For the short wall at the end I had to cut a really short bit of wallpaper, because I couldn't get a big piece to curve around the corner, so that's something to keep in mind.
Here's the way it looks now, after much repositioning and fit-throwing. The edges look raggedy, but I plan to figure out a way to fold them under and there's a windowframe that'll go there, too.