Not good - the 300MB language update I downloaded only contained a single manifest, and that was the wrong one.
Downloading the full 1.4GB package will not be possible until tomorrow, when I should be able to get to a landline.
If you have the media for Office 13 handy, you could try doing a Search for any of the more unique strings involved - e.g.
minkernelapinamespace 6.1.7601.17965_none 0c845227da39a5ef
but they are likely to be inside a .cab file which you would need to be able to extract, using WinRar or similar.
If you want to have a go, then feel free - if you find what you think is the right file, attach it to a replay, and I'll check it before we do anything rash