You mentioned having a .prefs file, have you tried importing your settings from that? If all goes well there, and this file is indeed a full settings backup file, that will at least get that kind of stuff back into the registry.
Also, if the font you refer to isn’t installed on your computer then Scrivener will fall back to a default, such as Arial. I am also wondering if you enabled showing invisible files and folders before giving up on finding AppData in the Windows.old backup? Try searching the web for tips on recovering data, everything I found indicates the whole user folder is backed up, not just the Documents subfolder. That would be ridiculous.