I own a '79 Benz coupe that is the spittin' image of yours, but mine is a diesel. The 280 gas engine is a screamer. Just keep the oil changed, filters clean and valves adjusted and you will love it. If the timing chain has never been changed, it would be a good idea to do it. That is about the only weak link on that engine. I have had my Benz for over 10 years and it is my daily driver. It has been relatively trouble free.
Also, being a Euro model like yours there are lots of cool features on it that the US models don't have. Enjoy...
