According to my research a Crossfire steering wheel is directly compatible with any Mercedes R129 W140 R170 W124 W202 W210 steering wheel. Not only can these be physically swapped but the electrical wiring connections (horn & airbag anyway) are also compatible.

Do your own research. IE, don't spend HUNDREDS OF DOLLARS without looking into it. But having spent some time researching this, it seems to be the case.