Ah, yeah. The rust stains are pretty bad. They're not unhygienic -- it's just iron oxide -- but they are undoubtedly unattractive on MOP.
Normally I'd suggest an ultrasonic cleaner, but I'm not sure it would do anything to that.
CA glue is surprisingly durable, but repinning that would absolutely require extreme care.
If I were doing it, I'd be breaking out every trick in the book to get the job done with minimal chance to crack that MOP.
Most likely, I'd use a
nail-set and every ounce of care I could muster for the job.
Swearing a lot when I fail, too.