Is there a Windows version of the Scrivener Project File (the one corresponding to the user manual)?
Oops, sorry. I didn’t understand the question; thought you were asking “what’s this ‘project file’ they refer to in the manual? All I have is a directory and a bunch of stuff in it…” 
The Scrivener Project file for the user manual that’s up on the Support page is for both versions; it’s all written in a single project with various sections forked as needed so that the draft can be compiled for just Windows or just Mac. You can download and open it in Windows if you’re so inclined. The main thing that you’d be missing is that the compile settings are for the Mac version, so that wouldn’t work properly for you on Windows. But if you just want to poke around in the project itself, it’s useable on either platform.