You could try using sanding or polishing bits on a rotary tool. They'd be small enough to fit inside the links.
sure. FWIW, this is the Reddit post where I discovered that diamond paste was a thing.
https://www.reddit.com/r/interestingasfuck/comments/sa7ycx/coin_polishing/
After viewing that embedded video, I purchased this assortment of diamond paste off of Amazon. If you enjoy metal polishing, especially small objects, I can assure you a great time ahead.
https://www.amazon.com/gp/product/B00NG3S6ZY?psc=1
enjoy
https://www.amazon.com/Drixet-Buffing-Polishing-Cutting-Compound/dp/B079X52ZG5
The description for this product should help. Buffs make a difference. Yellow is fast removal white is not as aggressive of a buff
Your polishing wheel won't pick up polish when it's new you need to use something to rough up the fibers. I made my own piece out of metal just cut a bunch of triangles and bobs your uncle
Actually that’s brass isn’t it? You might just want to go with never-dull for that.
Nevr Dull NEVER DULL POLISH 5OZ https://www.amazon.com/dp/B00097CRY6/ref=cm_sw_r_awdo_navT_a_YB28DCHWBEWY4E4WRAB5
You can probably find this stuff at your local stores too.