I always thought the Outdoor Recreation family of magazines is underrated; not only did they have great writers, but they also had many neat little articles on tips for anglers. Here's one from the May 1921 issue I never thought of but it actually works.
To Polish Spinners
by M. Welch
If you ever need an emergency polish for spinners or other metal articles, use an ordinary pencil eraser – the Faber red-rubber erasers are what I use, but any rubber eraser would probably work as well. Rubbing the metal with the eraser will give it a nice polish. It does nicely to clean spinners, rod ferrules, etc. Do not leave the eraser in the same tray with your spinners, as the rubber will ruth black if it remains in contact with the metal for a long time.
I wonder if this is why I find a lot of small pencils with erasers in tackles boxes from this era?
-- Dr. Todd