The most reasonably priced component used on the Ft500 Ascot 1983 (d) Usa Gasket Kit A is the O-ring,7.7x2.5.
Parts such as the Gasket Kit A: Parking,tappet Co (nas), Gasket.cylinhead (mca), Gasket,ex.pipe (nas), O-ring,7.7x2.5 are included in the Ft500 Ascot 1983 (d) Usa Gasket Kit A parts fiche.
Of all the components used in this assembly the Gasket Kit (nas) is the most expensive.