The 03-04 is different; Different fog lights.. different appearance. Not sure about what's behind the plastic cover though. I would just stick to the 99-02 cover. I'm partial to it myself. It's one of the more eye pleasing parts of the discovery 2. I wasn't fond of the face lift.

 

Upgrade time! Ditch the ARB (too heavy, pricey & bad approach >s) and go with one of a dozen other options with recovery points, jack points, winch tray, fog light, aux light mounts, brush bars, etc. Maybe the guy can paint it to match or something. Just me, but stuff breaking is my only excuse to upgrade most times.