Ok, I have a front suspension from a donor car that I have had for over 20 years. Taking it apart, and I noticed the rotors are original. Should I keep these old rusted rotors for any reason? I know there are a ton of aftermarket rotors, but does Nissan even sell them anymore? Would the original rotors make any difference to someone restoring to original? Hate to just recycle them if they have some use ......

Any thoughts

It's a dying skill but rotors can be "turned' on a machine to give a new braking surface.  It's actually cheaper than buying new rotors.  Find an older auto shop, or try a NAPA.

Out in Sunriver there's probably a bunch of places that do it.

If they're not overly rusted or pitted, they can probably be salvaged if they haven't previously been turned. There might be a restorer that might be looking for all original parts like "hiyabrad"

Older rotors have room on them to turn. New rotors seem to be designed to be trash when they get worn. Just not enough metal on them to turn them down