The most reasonably priced component used on the Fs1 1977 2g0 Europe 272g0-300e1 Crank Piston is the Washer, Spring.
Some items from this specific schematic: Key, Straight (260), Pin, Crank, Washer, Spring, Brg,r-b 6303 47mm 115g Nk.
Check out any of the thirty-five Crank Piston components enlisted.