Sadly it is not a case of what they are worth as a model for sale on the market such as ebay or any of the facebook forums.
When it comes to the antics of an insurance loss assessor, as they have little or no idea as to how many hours it would take to rebild or replace a model as such as some of those you have which even as bare kits would be anything from 3 -500 quid.
And insurance companies are not in the game of supplying you with the generosity of a Loss Adjuster to make sure you get a fair price.
The only way for you to get a fair price is to find someone with a good pedigree in building models to give you a price as to what they as a semi proffessional builder would charge, and justify in materials, time and cost of man hours what their cost would be, and put that in writing with their credentials and photos of their own builds..............
And even then you would be on a hard upward slope to even get what a modeller would charge you from an insurance point of view.
However, what concerns me is how many of those models still have the batteries in side the boats, swetting away, just ready to burst in to flames, and even sealed lead acid batteries can do that.
Always keep your batteries out of the boat and preferably in a cool shed.