You might try www.Mosselmanturbo.com. They make turbo kits for mercedes. They may have a kit or be able to fix you up with at least a partial kit. I have sent them a message to see what they have for us. I saw one of their twin turbo kits selling for under $4,000 Information is a little sketchy but it looks like they are getting another 100 HP from a Mercedes 6 cylinder with 6-7 lbs of boost.

If you fab everything yourself you should be able to use the stock exhaust manifold flanges with some new piping welded in. I think the exhaust manifolds will be the most tricky part of this. You might also consider a Rotrex belt driven supercharger which would require a bracket to mount it to the engine. Our engines have a perfect and natural place to mount this just above the alternator. I have seen kits for the rotrex where they have made a bracket that attached to the front of the alternator. I will send you a picture of this if you are interested in going this route. The rotrex is a new design that is very compact, gives boost on the low end like a roots style and performs on the high like a turbo.