Your best bet would be to take it to the shop and ask them to give you a quote on what needs to be fixed... perhaps more than one shop...
that gives you a list to work from... some things are not easy to check DIY..
I used to work at a spring and brake shop... they know how to place force in the right manner to check tolerances.

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1980 240d ,

chain elongation, cam marks reference:
http://www.peachparts.com/shopforum/showthread.php?threadid=10414

http://www.peachparts.com/shopforum/diesel-discussion/305365-9-degrees-chain-stretch.html

evap fin cleaning:

http://www.peachparts.com/shopforum/showthread.php?t=156207&highlight=evaporator

A/C thread

http://www.peachparts.com/shopforum/diesel-discussion/297462-c-recommendations-mb-vehicles.html