Looks like a 2001 Enduro expert. As far as mods, it's had a Chris King headset installed (upgrade), and the XTR crankset is an upgrade over stock Spec cranks. Looks like the original Hayes hydraulic brakes have been replaced with BB7 (slight downgrade but I prefer the BB7 for ease of maintenance personally). He probably ran into some braking issues with the hydraulics stemming from hanging the bike upside down.

Here's a link to original specs https://www.bikepedia.com/QuickBike/...spx?item=35753

There might be a catalog up on retrobike.co.uk if interested in other info