I have never seen the 6 speed conversion done.. but I know that the W203 2002 c-coupe has an M111 motor and a 6spd tranny.. it should bolt up to the W202 M111 block without problems.. just a matter of trying to figure out how to fool the ecu to think it still has an auto trans.
My thinking was to get a new 6spd out of a 2005+ w203 sedan and fit that onto my M111 block.. but I dont know if the tranny housing have the same bolt pattern from the M271 motor to the M111 motor.
the W203 2002 6spd still feels a lil slopppy.. but the 2005+ w203 6sp is very nice and tight.