im looking at it like this
with the silvia hood on the pop-up bumper and fenders you get this

I dont know about you but to me, if you were to remove the grill area and the two inch edge below each headlight and take
it right down to the bumper line, should be plenty of room for the silvia headlights
and the same thing for the fenders, line up your corners and cut less than you think youll need and adjust it slightly until the corner
fits flush