This Chain,drive #525tr-10 is the most expensive of the items that make up this Oil Plug - Oil Filler Pipe-drive Chain-gear Shifting Cam-kick St assembly.
In this schematic the "O Ring(d:2.4,id:21.8)" is used most often.
The most reasonably priced component used on the T20 Tc250 Scrambler 1969 Usa (e03) Oil Plug - Oil Filler Pipe-drive Chain-gear Shifting Cam-kick St is the Washer,lock.