Your mystery piece is from the fan clutch. That strip rides in the middle of the clutch and it's expansion or contraction (due to temp) determines the level of engagement. If it is from your present fan clutch then you will have maximun engagment assuming it isn't already completely spent. The fan clutch isn't cheap so if you don't have overheat issues I wouldn't worry about it unless your fan continuously "howls" from constant engagement. That eats up fuel mileage, running the fan full speed when not needed. If that is the case you have to decide where you want to spend or not spend your green.