That’s what I thought, it is not a switch though, he is talking about the ignition switch housing and not the switch itself. The switch may come with the housing I cannot say. That housing is expensive and that is why people fix the one they have, the mod makes it identical to the expensive new part, because that is all Mercedes did to fix the problem.
He does not advocate changing the part just modifying it as outlined. You would have to take the housing out to replace it with a new one, but five minutes work would make it identical to the new part, you just take out a spring and a little item.