I have also recently purchased a 82 300SD. I consider myself a basic fix it person. I have noticed my driveway is bearing the same mark of the diesel. I have pinpointed my leaks though. One leak was coming from the rubber boot(top of oil pan) where the turbo exhaust tube goes down into the oil pan. I was able to go under the car and lift the tube, twist the boot slightly and then move the tube back down. This seemed to solve this leak. The leak I am fighting now is under the oil filter where the hoses attach to the filter housing (bottom hose). Because of the location, I am having a hard time getting a wrench on this tube to tighten it. The only other problem I have had thus far was diesel leaking from the last fuel line on the injectors. I replaced this and it solved the leak. Good luck with your ventures. I am having a blast working with mine.