If you're going to change out the water pump, I'd obtain the proper repair manual first. For Euro 287 it's easy. He does it for a living. If you've never done one before, it will help to know exactly what all is involved and where things are.
1991 300-SEL - Model 126
M103 - SOHC
James Madison - Oppressors can tyrannize only when they achieve a standing army, an enslaved press, and a disarmed populace.
Liberty Firearms Training - After years of trying to regulate California criminals with a never ending stream of gun control laws they have still not given up with the belief that if they make something a crime that criminals will miraculously start obeying the law.