Thanks, that is the exact part# on the pkg. It's a genuine Mercedes part, has Mercedes name & logo on it. It looked identical to mine, till I had them side by side.
Yes, I saw the round actuator one too, I think it's for later models.
I took both of them apart to try to swap just the "rubber seal" from the new part to the original to try to make this work. But unfortunately, the "rubber seal" is molded to the stem....so can't just swap the rubber seal over.