If you are looking for a shop in the UK you might get more responses by posting on the NSX club of GB forum
As an observation, your HC seems grossly high. If the car is a 1994 the catalytic converters may have reached their best before date. Other potential guilty parties include
- leaking fuel injectors
- a dirty intake air temperature sensor
- tired O2 sensor(s)
- fuel pressure out of spec
Use the diagnostic test connector to retrieve any stored error codes. Those might give you a hint as to what might be going on.