NOS is a wank! Most of the NOS stuff I've seen is either shop soiled, rusty, cracked etc and when it comes down to it the person who has purchased the NOS parts, usually at ridiculous prices, is the only one who cares. Just because it's still in it's original packet or hasn't been used doesn't mean it's worth a squillion dollars. I have done many concors restos but most people don't look past the paint & plastic and if they don't have an emotional attachment to what they're looking at, they don't care what it is NOS or not. You'll send yourself nuts trying to do a NOS resto to boot!
Cheers,
K