Are you talking about the seat and backrest that will just screw on to the base?
If so, it’ll probably be impossible to match the original 1997 Lund Fisherman design. To get them to match you may have to replace more than one.
I read someplace (and I’m not sure if it’s true or not) that Lund original boat seats are only available for approximately 3 years after a boat model’s release date.