hard suspension

[Hocky]

My 1994 C180 Elegance is giving me the hard knocks over some even minor bumps and with 197000kms assuming it has original shocks, do I need to change now, all 4 shocks?. Looking under the car on a lift, both rear ones show oily leaks on the tubes. The fronts look dry. However when I try the usual hand pressure method over the 4 corners, they come out pretty well, no uncontrolled up/down oscillations of the body. Just one up motion and a slight down again to settle. How do I find out if the previous owner changed to the sports suspension rather than the Elegance one which is supposed to be the softer version. Is there a colour difference in the shocks or numbers or what on the shocks to tell? Do I have to change the springs too to "revert" to the softer setup? What would be the approx. cost on parts and labour time if all 4 are changed? I also feel that maybe the front left chassis is also loose if any or maybe other linkage parts are loose. Thanks.