Parts such as the Tires: Tube-tire,2.50-18 Tr6, Tube,2.75/3.00-18, Tire,rr,2.75-18 6pr K, Tire,fr,2.50-18 4pr F are included in the Ar50a1 1982 Usa Tires parts fiche.
The sub assemblies and components that make up this Tires include this Tire,rr,2.75-18 6pr K, the most expensive part.