Polishing with T-Cut or Brasso is good for bringing back the shine on local spots like that. Maybe try on one spot, and if it works, do the others, then follow it up by lightly doing the whole frame (to blend the shiny bits with the restored bits, although this will slightly dull the shine overall, and once that's done, a good going over with a liquid wax-based car polish to bring the gloss back up and help protect it.
Polishing with T-Cut or Brasso is good for bringing back the shine on local spots like that. Maybe try on one spot, and if it works, do the others, then follow it up by lightly doing the whole frame (to blend the shiny bits with the restored bits, although this will slightly dull the shine overall, and once that's done, a good going over with a liquid wax-based car polish to bring the gloss back up and help protect it.