Not my coin, owner believes it to be a 1873-CC Trade Dollar. I will admit I didn't have time to loupe this coin when I photographed it. Upon looking at the placement of the mint mark from NGC's website, I'm going to say... Maybe? The red line is where I believe the MM location should be. Below the upper red line is where I believe I see a pillar for the second C....
I think it’s got a good chance. I see the c. Here’s mine mine has a different mm than your coin. Different dies
"BooksB4Coins, posted: "Perhaps it’s better in-hand or some other attribute was used?" They could count the edge reeds.
I think there could have been enough to determine. I thought I saw the mm in pics and in hand is better
I cannot speak for "them" but that's the job and that's the way it worked at the TPGS's I worked at. Whatever it takes. That included trips from DC to NYC on a few occasions! I count the edge reeding on at least a dozen coins a month - either to confirm authenticity or for my diagnostic records. Been doing it since 1972. Started as an idea I had to authenticate one type of heavily counterfeited gold. Unfortunately, I discovered that all of the dates/mints had the same reed count! Happily, this is not true for other coin types.