Only way to repair the scratched audio on/off and engine start/stop is to replace the whole climate control switch box. There are some benefits to doing it this way and one caution I discovered too late but doesn't bother me, for my application.

The unit is almost $500 new. There are plenty available on eBay. Just watch for good photos on the listing. Obviously you don't want a replacement unit scratched like the one you're replacing. Watch that the mounting pegs are intact. Also, there are units without the CD slot, which I wound up buying. Not a big deal for me, haven't played CD's in decades but was easy to overlook when choosing a unit on eBay.

I don't know that it was 100% necessary but I started by disconnecting the POS cable at the battery. I've been screwed before disconnecting the climate control unit on a Volvo XC90, car off but battery connected, and it threw an SRS light.

I popped the two leather covered side trims off the center consul and the small black plastic skirt under the climate control switch unit and lifted the upper display's plastic surround's bottom edge. No need to remove it. Then it's easy to pull the switch unit straight out, disconnect the wire plug and swap switch units. Pop everything back in place and hook up the battery. Tailgate and auto up/down will need to relearn.

Side benefit to replacing the '17's switch box is gaining the Sync key that the later ones have.