Mine is 2090 lbs or 950 kilos wet with no driver or passenger. Surprised yours is not less than that Richard?
I too have a have a heat build up problem, which I have mitigated in several different ways:-
1 Fit an aluminium radiator with more water capacity
2 Fit bonnet extensions catches to allow heat to eascape from the under bonnet area.
3 Fit a fan override switch and use it to keep the temperature down before it reaches the 90s C
4 Do a complete engine and radiator flush (esp if the car has been standing for a while) to ensure that the cooling passages are not impeded by solids.
5 Use heat insulation beneath the leather upholstery and seal the gear lever and hand brake lever better.
Good luck
