Would it be possible to pay to get an evaluation by an NSX specialist?
I don't beleive an AA inspection is worth a carrot on something that specialised.
Maybe an endoscope into the sump, plug holes might reveal something?
I have known cars where the MOT tester's looked askance because of the very low mileage between annual tests, so it might be genuine.
The lack of FHSH throughout is very concerning, but given the poor reputation of many Honda (Incl. NSX!) dealers, it could be explicable.
Nick
“I find myself irresistibly attracted to cars that nobody else buys. The NSX is a classic of the genre because nobody buys it and yet it’s a fantastic car. It’s got a wonderful compactness and simplicity and unpretentiousness to it. Honda rudely continues to make them whether we like it or not, even though there can be no commercial logic in doing so — I thoroughly admire that.” Rowan Atkinson