I keep everything, rusty old Rotors Calipers, manifolds, nuts/bolts, greasy old engines, fenders, hoods, doors and .....and.... then when I kick off the kids can worry about all the junk the old fart kept, and why?
I pulled a few W123 and W126 front Rotors along with the Hubs. too difficult to remove them in the yards, so just leave them on.
I brought some of my old Rotors with me the next time i went back to the yard to get my Core charge back. well they didn`t have a Hub attached so couldn`t get a core back. I was charged the Core for the Rotor, not the Hub, but they still wouldn`t give me the core charge, co. policy.
Charlie