I am about to recieve an 86 300 SDL as a gift.

Is there such a thing as a Free mercedes?

From what Ican tell it is not running. Some friends of my In-Laws are selling their house and want the car gone, and I showed an interest in it.
What are some of the Habbits/qwerks I need to look at for the SDL? I think it has about 245k on it and has always had dealer maintenance done to it (the owners are fairly well-off).