86560 SEL and all others:
This is an answer on your second question : are 90s-2003 Mercedes as reliable as the 70s and 80s models? NO! and this is not MHO! My Indy and MB specialist confirmes it. Fire hasards? Just drop the word "fire" and you are correct!
I drive an own a '90 300TD turbo and a '94 300TD non turbo ( a 606 engine ). The differences between these two cars are tremendous ( in the advantage of the '90's W 124 TD ).