I can't find it on their website, but the fall edition of Roversnorth's news letter shows a:
Genuine Discovery I Headlamp Upgrade Kit
Replace you old pitted headlamps with NEW Discovery II headlamps. Get the look, style and improved visibility by fitting NEW updated Genuine Land Rover Parts. Kit includes two (2) new Discovery II headlamps. Includes bulbs.
RNK9923 Discovery I headlamp Update Kit........$129.00