Hey, I'm from Kentucky (how could you have guessed...) your English is fine. Seriously, the next time you are in, you could offer the guy $5 or $10 for the coins and tell him you'll buy them from him from time to time. Who knows, he might just put them back into circulation. My only instance of anything like this was in New York in about 1975 or so I was buying a paper and the coffee shop guy who looked middle-eastern was looking at a nickel. I noticed it was a V nickel and mentioned it to him. He asked what it was and I told him an old nickel. He started to put it back in the till but I gave him a shiny new nickel for it and he was happy.
The ol switch-a-roo. Ill give you 2 shiny coins for your 1 dirty coin. I'm trying it. Ha. This guy you could tell had zero trust for much. Automatically assumed I had a motive for giving him free info. Some of the Asian and Middle Eastern countries are pretty ruthless. Screw over any and everyone seems to be the day to day way of life for a lot of them. Till I walk in his shoes though.
Talking about shaking them around in his hand though reminds me of shaking two Alexander The Great Tetradrachms around in my pocket and pulling them out to show someone.