I have mine insured with Footman James and value assured, or whatever it’s called. I had to explain why I wanted to insure it for the amount and you have to be sensible so you can’t just say it’s worth a million pounds etc. I have mine insured for £16k. I also have salvage rights so if it’s written off I get to keep it without them paying less.
Basically you need to think about what you honestly want for it and you will need to pay extra for the privilege. Otherwise they will just pay market price which is probably quite difficult a there are so few of them.