[bbcentral]

If I'd known that it contained a script, then wouldn't I have implemented it on my forum 12 months ago instead of writing my own script?

Actually, now I see it.

I REALLY wish this had been more clear at the time when I did the upgrade.

It's been buried away here:
forum/impex/tools/

Anyway from the readme, the url is:
http://www.vbulletin.com/forum/showthread.php?t=178161

I still prefer mine though, I don't want logging or 404 pages or anything like that.

Mine has 1 step, upload the file.

The impex version has many steps:
1) Edit the 404.php file to point to the 404 page, and also include your database user/pass
2) Choose between a 404 and a 301 redirect
3) Create the 404_actions table in your database
4) Setup a .htaccess file to point to 404.php

But it's up to you, you can either upload my file and do nothing else, or you can use the one in impex and spend 5 minutes configuring it, after reading a 163 line readme file.