I have three of these beautiful, classic, Leeds & Northrup switches.
They seem to use hardware similar to the "low-thermal-emf binding posts" from L&N used in my Keithley 260 Nanovolt Source.
The body is real bakelite, and the metal is some kind of copper, not plated, possibly Be-Cu (?).
They are are a bit old, but in good condition.
What cleaning product and technique are recommended for the switch metal parts?
I don't want to use an abrasive, but I also want to ensure the surfaces are free from copper oxide, which has a high emf against copper.
The photo was taken above a 0.5" grid.
![L&N low-thermal-emf switch cleaning](https://www.eevblog.com/forum/index.php?action=dlattach;topic=324409.0;attach=1484425;image)