Mike,
It is highly unlikely your commercial policy , as a Dealer , has any provisions for diminished value. It will show up on the Autocheck, Carfax, etc. , so the best bet for the Dealership is to probably advertise them as " Great Deal," theft recovery cars..........highlight no damage.
Bummer for you guys and really sorry, but I know the other vehicles we have had stolen off our lot, we had to take the lumps and go forward. Very sad about the Vipers, and though it is no consolation, getting all the cars back will make it easier to get a settlement. When one disappears from the lot and does not come back , you can imagine the delays.
Best wishes to you with this extremely unfortunate situation.
Respectfully,
Bill Pemberton
Woodhouse