Turns out this office has a VLK for Windows and Office, so I could just use my Windows XP VLK CD.
Windows installed fine, the problem now is with Office 2007.
The company has an Office 2007 Volume License, and a valid Office 2007 Enterprise key.
....but the Office 2007 Enterprise installer flat-out rejects it. I gave Microsoft a ring (long distance, because I can't find the Activation/Key support number for the UK), they said it was legit, and since it is legit they can't provide support (for that
I'd have to give Microsoft UK a phone call.... but they're Monday-Friday 0800-1700).
Yet another case of where being legit is harder than just torrenting the latest cracked ISOs.... are you listening Microsoft?