722.9 - ISM to non-ISM conversion??

I bought a w212 transmission for my w204. The w204 uses a lever connected to the shifter, the other uses an electronic control module and servo to select gear. Is there a way to add a lever to the w212 transmission would that work, or would it be easier to replace the internals of my w204 with the internals of the w212 (clutch packs and pistons)?