to be a legit series 2 i would expect
- series 2 interior
- series 2 dash cluster (bevelled warning lights, s1 has flat dash lights)
- series 2 dash (bubbled and textured, s1 has flat matt black)
- series 2 wing
- series 2 engine and front bar, lights, bonnett
- 1996 VIN or build date, anything pre 1996 is almost always 1.5 or 1
- series 2 boot SKYLINE panel is same colour as car (s1 has clear panel)
- a silver rear trunk lock badge
- dual airbags
- no coin holder near the mirror controls
Added 3 more changes to paulr33's list.
The most obvious change is that series 2 has dual airbags. Series 1.5 only driver side airbag and series 1 no airbag whatsoever. No matter how you see it, the airbag is the one thing no one can change hence it you only have what you have then you know what series skyline you have.
You can have a series 1 with series 2 bumper, fog lights, engine and whatever, if you ain't got dual airbags then you ain't got a series 2. Same goes for the other two series. Basically i like the series 1.5 cause it doesn't have the damn heavy passenger airbag and the external ABS module at the center console. Damn module makes the pocket smaller.
I have a series 2 skyline and i changed the boot skyline to a clear one and my trunk lock is not the series 2 one as well so i have a series 2 front end and a series 1 rear end. Even the agent here says why the f**k do i have such a weird skyline. lol