Did you sell the sandcast? After waiting for the seller to come around?
One option, if you still have the sandcast, is to increase your homeowners 'personal property' coverage in case of loss, or have an umbrella policy.
I have one myself, picture of the vin, which at this point in the manufacturing was on the left side of the gooseneck:
I'm eventually getting around to the resto, for now I just keep the engine turned over periodically.
It is a real iconic early model, sort of like the H2 but more valuable even than the H2's are. Once you have one it is hard to part with, they don't come up often.