What's needed for stock steering wheel change?

There is a plate with a bolt that is specific to this horn pad. See my picture. Doubt that anyone makes it so you need to be sure it is included with the setup that you buy. The steering wheel mounts to the column with the nut just like most any other wheel including your S83 wheel. Then the horn switch is screwed to the wheel. Then the plate is screwed to the horn switch. Then the horn pad is bolted to the plate. Then the emblem plate snaps into the horn pan hiding the bolt. Vala.