Many thanks to everyone that has commented and given me the confidence that I've done the right thing.
So here's the latest update: I've just returned from Emblem Sports Cars' Saturday Clinic, where Darren and Tim spent nearly 3 hours looking over the car, including a test drive and a session on the ramp.
Firstly, they both agreed the car is superb. Very little to fault and a lot to complement. The car has clearly been well looked after throughout it's life, so another load of thanks to Richard (who's just sighed relief!).
Secondly, what a great service Emblem provide. Practically everything that could be checked in the time was checked, including SD3 analysis, oil levels, brakes, ball joints, parameters, even removal of the rear under-tray to look at the gearbox and search for leaks. And it's all foc.
Took the car for a short blast up the local A35 - phenomenal. What a car.