I have a 85 190E2.3 too (with 127K though - its good to know that yours has lasted 250!) - makes the exact same noise when going over bumps, front driver side. The noise is more pronounced on colder days. Showed it to a guy, he told me to get the front "driver" side idler arm, tie rod, etc. and ball joint replaced, and wanted me to make him richer by $1000, without guaranting that the noise will go away. Well, I have moved to another tech obviously.
My reading of the situation leads me to suspect the front swaybar bushings. When the car was jacked up, I saw the front driver side swaybar bushings kind of squished. Get those checked. I am going to get them replaced on my next service.