Drove the car home several hundred miles with the old carb, a gearbox that wouldn't shift into third and a sticky kickdown linkage. Gearbox and linkage now serviced, still chasing an overheating issue but that seems to be down to a faulty gauge. Goes right up to 100% within the first ten minutes before the (new) thermostat opens, then settles at around 70%. No actual signs of overheating though, checked with an infrared thermometer.
With the rebuilt carb I covered around fifty miles but not in one go.