On this parts fiche the O-ring(1ux) is the most specified component.
The ten Xjr1200sp 1998 4pub Sweden 284pu-300ea Cylinder component parts are all listed in this schematic.
Parts such as the Cylinder: Nut (6ta), Nut(6ta), Gasket (1l9) (nas), Bolt, Stud(4br) are included in the Xjr1200sp 1998 4pub Sweden 284pu-300ea Cylinder parts fiche.