It looks like those scratches go pretty deep. When they were originally plated, they most likely had a layer of copper, followed by a layer of nickle, and finally chrome. I'm going to guess the layer of chrome and nickle are pretty gouged?
One "last resort" method I use with really rough chrome is four ought "0000" steel wool wetted with Turtle Wax Chrome Polish. That will usually take care of surface scratches and moderate rust.
For those steering wheels, I'd try it first on the backside and see how the surface is holding up and that you're not rubbing through the plating. If you're able to remove some of the scratches, switch from the 0000 steel wool and just use a towel wetted with the Turtle Wax Chrome Polish.
Another option would be buffing rouge and bonnets from Harbor Freight if the steel wool isn't cutting it.
If all else fails, see if there is an industrial buffing / plating shop in your area and get their opinion on buffing or plating since the plastic could potentially cause trouble.