Flea markets are some of the last Bastions of the Great Deal in America. There's a guy at our local flea market, shows up once a month or so. He has a box of coins that he sells for 1.00ea. I've found tons of Mercs and even a Walker half. But the hunt is 75% of the fun. Remember Ferreram if you liked the JFK coin and you are satisfied with what was paid for it, it was a good deal.
That 43-S merc looks like EF45 to me except the full bands are excellent and could drive a AU-50. I like it a lot!
I too think it may be as high as an Au. It still has all the mint luster. I wonder if it could make it to an AU-53 or even as high as an AU-55. My only concern is the Reverse. The "ne" in one seems worn down a bit as well as the "e" in states. Any opinions as to the Buffalo? Also do you know anything about the Liberia coin.
If it's got nice luster, you're probably right on the mark with an AU-53. Your pics leave a lot to be desired in terms of luster. As for the Buffy, looks like it's heavily corroded on the reverse? I'd say it's got F details, but a G net.