Welcome back Dale.
As I understand it, you'll have to look at the number on the balancer & see if it is the latest ( " New & Improved " ). number.
Other than that, your local M-B dealer can probably tell you from the VIN, if it has been replaced.
I would also check the front spring perches on that model, to see if they are corroded/seperating.
The rattly cat maybe worth mentioning to your dealer as well.
Maybe you'll get lucky , with the dealer that is.

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2007 C 230 Sport.