Not sure about trouble spots.
My old mechanic had one and swore by it.
But then again he knew I really liked it and kept trying to sell it to me.
(Both he and his wife were driving 99 S500's at the time, and their daughter would not be caught dead in the '83?).

I think he wanted $3500, but probably would have settled for $3k, to get it out of his driveway. The only thing that kept me from buying it was the color, dark blue, with blue MB tex interior. I do not have the patience it takes to care for a dark colored car.

The one thing I can attest to is that you will enjoy the car ten-fold if you buck up for good tires and get new suspension parts. Good news is most of the work is DIY, and you can save some serious coin by shopping around (this site and others).

I thought my 85 500SEL rode nice, until I test drove the mechanic's 83. It was enough to convince me, and he helped me do much of the work myself (of course I also spent $600 + on other mechanical needs that his shop was set up for).

Good luck - Michael