You can search eBay for sold listings but it doesn't have many V11.
But you could take sold prices from some of the other models and compare those to NADA prices to prove they don't align?
I would also try and be a real thorn to the adjuster if you can contact him, explain how these bikes are on a collectible ladder and you planned to keep it as investment, show him a couple sold ads for a1000s as example He won't know the real differences..?
Have him just try to find a replacement for anything close to that low figure. If you can't find one in that range how can he justify that amount? Also have you told them your riding gear and boots were destroyed too and you want pain and suffering money? You can work this if you don't give up.