What To Use To Clean Staining Off Feathertouch 2-Tone Nib?

[Intensity]

I have a Sheaffer pen with a dual-tone #5 Feathertouch nib, and all is well with it, but there is some red staining on the top of the nib near where it enters the barrel. The rest of the nib is clean and shiny. I'm not sure what caused this staining (I got this pen like that from someone else), but I'd like to try and remove the reddish stains. The red seems to be more like ink color, toward magenta, not orange of rust or anything like that.

 

What products can I safely use to clean up the staining from this nib?

[Blueberry567]

A sunshine polishing cloth would do the trick

[3rdlakerobert]

Since the stain is on the unplated part of the FT5 nib, I wouldn't hesitate to try Semichrome on a Q tip. If it were on the plated part, I'd do the same but go easy.

[siamackz]

A sunshine polishing cloth would do the trick

+1 if its on the gold, unplated side, as even sunshine cloth will take plating away little by little

[PAKMAN]

+1 on the sunshine cloth (jewelers cloth)