I just bought a '81 300D with 81k miles. I don't have the service history and I bought it from the 2nd owner who didn't know its service history either. It appears to be in excellent condition. Besides changing the oil right away, what else should be done? On my to-do list, I have: check/replace timing chain; adjust valves; replace fuel filter/conditioner (there is one, right?); flush brake fluid; service auto. transmission; and flush cooling system. What do you think? Any suggestions? How important is it to get a certified MB mechanic to do this work (I have a very qualified mechanic, but not MB-certified)?