Thanks for the welcome and tips guys. I've emailed the seller to see if he has replaced the clutch/exhaust.
The Parkers price, corrected for mileage, for a 2004 04 GT at 65k is 10k these days so if he hasn't replaced these parts I will have to offer less.
I'm sure the current prices depress existing owners, but to me it's great - until I try and sell my lovely - albeit relatively slow - MX-5 I suppose!