I would check frame welds, 1st Gens were known to sometimes develop cracks the the frame welds, especially if the bike was abused. In the '04's The generators could grenade the engine and need a shim to keep it from doing that. The '05's didn't have this issue. If you search for it here you can find a lot of info on both issues. The 1st Gens were also named 'Widowmakers' for having a very bad disposition when slammed to full WOT. Headshake is a major issue and a damper is advised to be fitted.
That said, I would not hesitate to own one. I've owned an '05 and loved her dearly. I miss her to this day and wish I never sold her.