At that mileage, i would be inclined to replace them all, but then I am pretty obsessive. Someone (Dalton???) posted this pic in the past, it may be of help.
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John
2003 Firemist Red/grey leather SL 500
2015 Palladium Silver/black mbtex GLK 350
1987 Smoke Silver/burgundy mbtex 300E Sportline (SOLD)
Click to see 87 300E