Read the links that I provided, and get the better gasket kit. Do a lot of studying, and you will learn how to repair them, and eventually, you will become the guru of that particular carburetor. There are people that only work on Carter AFB's, and others that will only work on Quadrajets. Carburetors, as simple as they are represented to be, require a high level of knowledge of how they work, and what goes wrong with them. I know the Rochester brand of Carburetors, up till they switched to the Quadrajet, however, I never learned the Quadrajet, and I don't even attempt to understand them. Carburetor repair people are either general practitioners that work on all makes and models, or they are specialists. You need to either become the specialist, or find a competent one. See if there is a local independent Mercedes Benz specialist that is willing to help you resolve the issue at a reasonable price.