Its a 97. 98s were Sport Corsas (which in addition were not sold in the US). Header pipes are stock appearing, not an expensive Guzzi racing exhaust. The exhaust crossover appears that it might be the one distributed by Rex Marsee, who was the MGNA west coast rep. in 97. It was sold with a chip that was a direct copy of the early Moto International chip. Both were relatively poor quality, I think the crossover was made by Cobra.
Front turn signals arent stock, Id prefer stock. Stock mirrors arent mounted. Front brake discs are 996 style, better than stock. If you look very hard at the rear disc it appears to be the original, with the shoulder machined in the wrong place (Guzzi gave you a new one if you complained). Hard to tell about the front fender, looks like maybe an Agostini CF part which would be good. The clip-ons are not stock, cast aluminum versus steel, but appear functionally similar to stock.
Mileage is average at 28K. The bike looks clean but its hard to tell with the filter applied to the photos. The extra (UK?) license plate is weird
