I bought an 85 300 tdt sight-unseen and I have been very happy with it. Looking at your car, I see you have a climate control system like mine, which was a European import, not the push button type. Do you know if the car was sold in America? It does look like it has those big American bumpers. Hopefully someone more knowledgeable will chime in.

My car was a European import and could not be resold in the USA, so I got a good deal on it. ( I imported it to Canada) My story sounded a little like yours, an old German guy had imported it for his own use. The story is here

http://www.benzworld.org/forums/w123-e-ce-d-cd-td-te-class/1232765-how-does-one-legally-sell-grey-market-w123.html