The 2004 roof rails are unique in that they are round in cross-section. The cross rails for the 2004 are also unique for the model year and hard to find. I just came across this Craigslist posting showing a Vancouver, BC dismantler selling the cross rails. One of you 2004 Disco owners may want to snap it up quick:

PARTING OUT / DISMANTLING 2004 Land Rover Discovery 2

P/S. I am not affliated with the seller.