[ZeGermanHam]

Why not just wire-wheel or sand away any rust on the headliner rods and then prime & paint with rust inhibitor?

Also, FWIW, the headliner rods in my car had surface rust, but there was no discoloration on the original headliner when I removed it to restore the car. Regardless, there's no reason why you can't simply clean up the rods and use them again. Should only take an hour or two to do yourself.