What you want to do to your 190E is a reality
and there is a front cap section available that welds to the front of your hood. This resembles the C class profile and then you install a C grille assembly. More info of this conversion can be found at in-pro, located in California and on the net.
Good luck, show us pictures and comments if you go ahead with it.
300CE, 400E, C280Sport, 190/5.0