I had a 91 NSX (manual transmission) few years ago and mine didnt have the power steering wheel.
Im not sure but 91 models with manual transmission didnt have power steering wheel.
but only the models with, auto transionnion has the power steering.
Once i drove Miami to LA and the handing was perfact. no problem even if there was no power steering wheel.
However, when I was in the parking lot!!!! haha... I had to use two hands..