Likely the oil on the engine passenger side is related to the rattle. The aircleaner bracket is broken, so its rattling around. Allowing oil to leak from the air/oil seperator in the air cleaner.

I'd offer $1000 or maybe $900. But I'd be willing to pay $1400 if I were looking for another one.

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'84 300CD Turbo 132k (Anthracite Grey) - WVO - My daily driver - Recently named coo-coo-coupe by my daughter.
'84 300D Turbo 240k (Anthracite Grey) - Garage Queen
'83 300D Turbo 220k (Orient Red) - WVO - Wifes daily driver

I'm not a certified mechanic, but I did stay at a HolidayInn Express last night.