The steering column is a GM but not sure what model. You may be able to get a newer GM steering wheel to fit it. But it would be more than the wheel since the base would have to have the clockspring for the extra controls.
It would be easier and cheaper to add a stereo controller like this: CD-SR100 - Steering Wheel Remote | Pioneer Electronics USA
Even if you have to change out the radio, that's on my short list.