So I need to reshim it then you mean? They're not adjustable in the sense of mechanical lifters but there are like 30 different shim sizes offered. Now I just need to get my hands on a valve spring compressor and a go-no-go gauge...(stupid Mercedes tool prices, compressor is $140 and go-no-go is $60, maybe I can find someone who rents them).

And yeah, I did check with a Mercedes specialist I know (but he's not around here, so it was by e-mail, he didn't visual inspect). He had no specific ideas.