What to Look For When Buying?
 

Has anybody put together a comprehensive checklist of things to look for in the drivetrain, suspension or body before (preferably) or after buying a W123 or W126 sedan, particularly a diesel?

I want to take my time and make sure I get the best car I can, but I have no idea what things to check for that may be peculiar to Mercedes diesels.

Thanks for your help

Gary