I see we've got the usual guesswork and 2nd hand information posted up already... Not only are you insuring a left hand drive car it's also an import so the regular insurance co's just haven't got a clue.
I've got a classic american car and they are surprisingly cheap to insure at any age. However, you don't want to bother with compare the meerkat et al. There are a number of specialist insurers out there who will deal with american cars. I've got mine with adrian flux although it was a toss up between them and RH.
I know a young lad who picked up a '67 coronet last year. He was 19 and he was paying something like £1300 and change which is an awful lot of money to insure a car even if it is a 6.2 litre V8.
They are quite cheap because they are statistically unlikely to be crashed. There are thousands of snotbox corsas et al smashed up every month. I bet you could count on 1 hand the number of claims submitted for corvettes and they are considered to be VERY popular american imports.
My yank tank came in at £133.
29 / 27 yr old, 1 SP30, reasonable postcode, 6 years mirrored NCB, 5k limited miles fully comp and inc an agreed valuation.