Mercury online parts diagram shows three items, #57, #58 & #68, between the Thrust Washer(#64) and Anode Kit(#56A) that are missing from my unit. In addition, I have a Lockwasher between Washer(#65) and the prop that is NOT shown on the diagram or listed in parts list. Do I have a real problem or is Mercury Parts System screwed up? NOTE: Since boat was new, have always had significant "clank" when shifting into reverse and sometimes engines stalls. Is all this related or separate issues? Thanks for any help!