A sample from the products for the Fuel Tank (gsx550esd) include: Tank, Fuel, Cushion,fuel Tank, Cap Set,fuel Tank, Cushion.
On this parts fiche the Emblem is the most specified component.
The most reasonably priced component used on the Gsx550ef 1984 (e) (e01 E02 E04 E16 E17 E18 21 22 24 25 26 34 39) Fuel Tank (gsx550esd) is the Washer (6.5x24x1.6).