I'm beginning to think sectshun8 is right. The 1741 is not numbers at all, but symbols.. More like "one... seven... upside down seven... one." You can clearly see the "ones" are not really ones, and the sevens are split in the center, which would make them not sevens, but a symbol.
If they are a coin from Constantinople, they have no business being in the ground in the USA. And if they are made from bronze, that not an easy process is it? Who would go through the trouble of making a token or gaming piece out of bronze? They would use some junk metal.