Hello everyone. As the title suggests I just picked up an 82' Mercedes 240D. I got it from the original owner and it was sitting stagnant for a couple of years. I have already changed the oil. I also plan on taking care of the following:

-Change air filter, fuel filters, and power steering filter and fluid.
-Flush coolant system.
-Adjust valves and replace valve cover gasket. (If anyone has a video on valve cover gasket replacement I would appreciate it.)
-Replace glowplugs. (Does this need to be done or should I test them first?)
-Charging AC with R12.

I was also considering doing a diesel purge, although I am concerned about the necessity and safety of this procedure. Can this be harmful to my engine and if not, would you recommend doing it? The car only has 95k original miles.

Also, when charging the AC is it necessary to evacuate the system first? I don't know when it was driven last. My guess would be two or three years. I have heard arguments for and against R12. Would you recommend charging the current system or retrofitting and charging with R134A?

If there are any other maintenance items you would suggest please feel free to share. Thanks all!