1991 420SEL. While replacing vacuum valve/check valve the one located on the false fiire wall MB P/N 126 800 00 78 (yellow and gray) the little tit on the inlet side fed from the intake broke off. And, the starred "nut" that holds it in place desintegrated during removal. I ordered a replacement only to find it doesn't come with the "nut". I just assumed it came as a unit. I checked every site that sells parts and none of the pic's show it with or, as a separate part. Calls to the vendors and they don't even know what I talking about.
Does anyone know where to get a hold of the "nut" for this valve or,the P/N?

TIA, Dave