The thirty-one Gs500e 1991 (m) (e01 E02 E04 E15 E16 E17 E21 E22 E24 E25 E34 E39 Seat (model S/t) component parts are all listed in this schematic.
Of all the components used in this assembly the Seat Set is the most expensive.
On this parts fiche the Cushion,seat(40x20x15) is the most specified component.