Trade dollars were made specifically for trade in the orient . They were distrustful of coins that might not contain the proper amount of silver . So they would test a few for fineness and then punch in a personal mark or chop to identify them as good coins . The chops look like Chinese characters in writing . Some might have one punch or as many as ten as each chopmark was known in a specific area . Sort of like if your town put a mark on it and then another official from another area would put his mark on it . Try googling chopmark . if this didn't help .
Ironic, isn't it, that the Chinese of that day didn't trust the specifications of our government silver, but today they seem to have no problem flooding our market with fake crap.
I'm sure they had no problem trusting the specifications of our government silver, they were worried about counterfeits not made by our government. (Possibly made by other Chinese.)
There is only 1 chopmark. When i see marked trade dollars, they ussualy have a lot of them. That peice is really nice, the chopmark is not that distracting. I Approve!:smile