Personally I think they look great just as they are, I'd leave them well alone. Great finds by the way, cheers.
This is my method of cleaning badges and buttons.
You will need.......
1. A pack of tough scourers, the ones made out of strips of stainless steel coils.
2. Brillo pads
3. A small brass wire brush, like the ones used to clean suede shoes.
And to clean the badges.......
1. Using a bowl of hot soapy water, scrub the relic with the scourer. If it has little recessed bits, use the wire brush to get the muck out.
2. With the soapy water, scrub all over with your brass wire brush.
3. Rinse and dry the relic.
4. Now, using hot clean water, (without soap !), use the brillo pad to scrub the relic.
5. Rinse and dry.
Hey presto......clean relic.
There is a further step you can take if you want to try and get the relic back to whiney brass, but do this with caution!! Simply soak the relic in white/distilled vinegar for 12 hrs, then repeat all the above.
Could I add that only do Steves remedies on the relic badges, ie the Russian badge is enamelled, DO NOT USE A SCOURER, warm soapy water only just to remove any dirt, then wipe and dry with a clean cloth
Thanks for the ideas
Will post photos when done