instead of peroxide put some tape on the dirty ones and push the tape into all the grooves and details and pull the tape off, do this a few times to all of them and try different tapes as well
Sweet. That semi key date is in great shape as you can clearly read the Liberty I like preoxide, soap and water, nothing else except maybe a thin coat of olive oil then wipe it off real good. Don't leave it on. To me it's like using armor-all Brightens it up a little.
Did you look at the 1873 to see if it is a double LIBERTY? You should be able to see it no problem. Nice 1876. I have one on EBAY right now. It's at $41 with a day left. Ground found also. NICE FINDS!