I've been looking into the same thing lately. After seeing all the VX accidents this winter, I started wondering what the "real world" market value of a VX really was depending on whether you were talking with a bank (for a loan), an insurance company (when deciding whether to total or not), or a buyer/seller to determine selling/purchase price.
I asked my current insurance provider (Pekin) what options I had for the VX, with my questions centering around the low production numbers for U.S. VX's, the VX being considered a future collectors' vehicle, and the limited mileage per year I tend to put on my particular VX.
I'd seen a Hagerty Insurance plaque in my agents office, so given the specialty vehicles commercials they show on tv, I asked if a policy could be brokered through them. While Hagerty said my VX seemed to fall closest in specifics to one of their Exotic Car policies, the one thing it didn't qualify for was overall value. Vehicles for their "Exotic" policies had to have a rated value of at least $40k. (Given the scarcity of Vx's these days though, who knows, that may be an option sooner than we think).
Anyway, that led my Pekin agent to tell me of their policies which included "stated" value, where it was a matter of getting an appraiser to write off on the value I wanted to declare. That's when I brought up the circular Edmunds/KBB/Insurance industry valueing system, because when I started asking just who I would have to talk to in order to get such an appraisal, my insurance agent was at a loss.
I still think it would be worthwhile to go with a stated value policy, so if any of you have insights into the specialty vehicle arena for getting those sorts of appraisals, it may be an avenue worth further investigation.
Hope everything is still going well Kodiak, for both your father and your VX.