Why do you refer to them as "NA1 headlights"?
NA1 is an engine code for the 3.0-liter NSX engine. That engine was included in all '91-96 NSXs and in '97-05 automatic NSXs. (The NA2 code is for the 3.2-liter NSX engine included in '97-05 manual NSXs.)
The NSX has had two different versions of headlights, which have no correspondence with the engine code. All '91-01 NSXs, both NA1 and NA2, had retractable, projector beam headlights with conventional bulbs. All '02-05 NSXs, both NA1 and NA2, had fixed, HID headlights.