You may need to talk to someone higher up at your insurance company.
Sounds to me like everything hinges on what's meant by "take delivery". Just because it's not at your house doesn't mean you don't own it. If ownership passed from the dealer to you, you "took delivery" wherever the RV is now.
One exception:
If the "deliverer" is employed by the dealer you bought it from and delivery was terms of the sale, then the transaction isn't complete and the dealer remains responsible until the rig gets to your door.
I think you need to get this straight lickety-split- if the dealer doesn't "own " it, he's likely not responsible for it any more than he would be if it was left there for storage...which it has, in a way.
