Joe,

Surely rads are designed to have air flow through them so you shouldn't really have to 'force' it, sounds like you could do with a new rad really? Lots of bent fins?

The bonnet vents will deffo not be helping your problems. Sitting in the ford fair queue last year I went from borderline overheating to a healthy temperature just by putting my bonnet on the latch, even with the car not moving.

Temperature issues arent always related to the cooling system, have you had the ignition timing checked? Fuelling?

Hope to see it at Ford Fair