Rotor rubbing

[Tailwind]

Hi All
Been working on the suspension. Replaced struts, top mounts and strut bearings.
After doing the fronts, I saw the drop links were shot and replaced them. This fixed clanking going over bumps, so decided to do the rears.
The seller gave me a pair of new Porsche rear rotors and Ate parking brake pads, so I fitted those as well. After all that, the right rear rotor is rubbing lightly on the backing plate.
the sound is a light tinny scraping that is detected loudest if you listen at the rear of the plate. to eliminate any other issue, I'll mention this:
Ended up removing the caliper and parking brake shoes.
The hub is quiet.
I swapped the rotor from the left rear for sanity check, same noise. I put one of the old rotors on, same noise!
We used the alternate method of taking the wheel nuts off when installing the rear struts, but my buddy (retired Porsche mechanic) had sold his big torque wrench, so he estimated the torque (this guy knows what he's doing), and I'll mention that there was no scraping after that. I have not taken it for alignment yet, as I'll do that after r/r the stiffening plate after changing the trans fluid.

Any wisdom? As always, I appreciate the forum members' advice.

TIA