Colin isn't the reg anymore since last year it's now Jason - if it's a valuation done by someone official then your best bet is to join and get Jason or another reg more local to take a look for you.
Failing that my insurance cover didn't require an owners club valuation and rather than going in to the ins and out's heres a thread that was active the other week that will give you a bit of info
http://www.escortrscosworth.com/foru...ad.php?t=32554