Honestly, you would have to redo the sub-frame bushings, engine mounts, control arm bushings, ball joints, fronts struts, rear shocks, rear suspension links, sway-bar bushings, and even new springs to truly get an example of what a new W124 rides like... but even then you may start to run into frame flex and metal fatigue with a 24 (1986) to 15 (1995) year old car with high mileage...
My W124 rides a bit rough, I need new struts and shocks bad, and I think one of the right rear suspension links lost a bushing so it is rattling...
