For my sins I've just purchased a Julie Labs 7 decade Kelvin-Varley Divider, and as far as I can tell, it works to spec

However, the screw terminals and spade contacts on the wires have the patina you would expect on a device that was probably manufactured in the 50s. So, what's the best way of non-destructively cleaning them?
A couple of parameters:
- I'm not interested in aggressively stripping back to pure copper. I'm not a metrology lab, so I'm interested in repeatable practical connections - and not interested in the ideal but impractical connections
- available chemicals are IPA, meths, Caig DeOxit, or anything else that can be justified
The terminals, shown below, don't look too bad. The spades connectors are muckier, but more easily replaceable. (The cables are very stiff, and feel like homebrew PTFE wires)
The "do nothing" option is perfectly reasonable - and is preferable to permanently fouling things up.