Does anyone know if a 1999 brush guard would fit a 2003? I believe it is oem. Thanks.

 

I recollect the bumper profile for the 1999 is different than the ones for the 2003/2004.

The old factory brushguard on my 2003 Disco (parts # STC53175) was not interchangeable with the pre-2003/2004 brush guards.

Here are the examples of the various factory brush guards:
Rover Connection-Land Discovery Brush Bars

The factory tubular brush guard comes in two versions:

STC50022 Wraparound Black Steel Brush Bar (99~02)
STC53175 Wraparound Black Steel Modular Brush Bar (2003~2004)

It appears they are not interchangeable between the 99-02 and 03-04 models.