the problem is the market isnt up there like it was and to be realistic an hz sandman restored is worth 30k at the moment...insurance companies only go on the market that can be proven like auctions that are real...ebay prices or australian muscle car sales are not recognised.
ive got an hq 350 gts coupe which was seen and valued by shannons during the boom..85k was the best i could get even when there had been another sold for 100k and our car left the other hands down for originality...
just recently i rang shannons and lumleys to insure a comparible car and the best i could get was 65k..

and thats simply because of the market...