Two years ago I test drove an 83 380SEC that an MB dealer was selling on condignment. They were asking $25,000. I test drove it and the only reason I didn't buy it was the price was too high. I test drove another one from a grey market dealer, and there was a noticeable diffence in power in the euro version. They only wanted 7 grand, but it was a grey market and I later found out the car had been rolled in an accident.
You don't really see many of these models. You'll see alot more 560SECs, but they are great cars. I think you will surely need to have the car converted to a double row timing chain. At 135,000miles I can't believe it hasn't been done. Be sure to factor that into the price you pay if you buy it. I don't think $7,200 would be too high a price at all for this car if it had the double row chain conversion.
Some things to check for are the seat belt extender. These cars early cars that offer the sear belts to the drivers have been known to have malfunctions. Which radio is in it? Is it the Becker Grand Pix? If you can find a Becker dealer see http://www.beckerautosound.com)
they can easily repair and refurbish the unit for a reasonable price, if you are in a hurry they might do an exchange, a refurbushed unit for you current one, plus a fee of course).
Do a search for the clock, I'm not sure how hard a fix that would be.