Seeing that picture almost made me throw up! That's horrible. As crazy of an idea as this may sound, you ought to tell UPS that you are going to be shipping the damaged grill to Rick's Restorations in Las Vegas to be repaired and that you will be sending them the bill. As a rule, whenever I ship anything "Weber related" that is highly prized, valuable, irreplaceable, etc. I always declare the value at $1000 minimum no matter what it is.
Personally, I think this whole "insurance" thing is a big rip-off that was invented by these shipping companies as a way of making more money. What other business can you think of where you have to pay additional money just to "insure" someone does their job right? When you order a pizza from Dominos, do you have to pay "insurance" in case they drop your pizza? When someone puts a new roof on your house, do you have to pay extra to "insure" it doesn't leak when they are finished? If you go to Midas to have a new muffler put on your car, do you have to pay extra to "insure" it won't fall off when you drive away? Why should shipping be any different? It was in their possession the whole time. The damage occurred while in their care. They should make it right no matter what it cost.
Sorry to see that this has happened.