There are places that do steering wheel restoration and I've read about guys using home repair with various epoxy putty products like POR15's or Eastwood's. I don't know how well either repair holds up long term. Here's a couple restorers I've seen mentioned. I don't know much about them but note the wheels in their galleries of restored examples. http://garyssteeringwheel.com/gallery.htm and https://qualityrestorations.org/pontiac/
