Your coin is a known die pair, and the issue has been talked about off and on for a few years. The consensus has been that it is not a repunched mint mark. This die pair was abraded heavily because of die clashing. You can see the distinctive die polishing next to the buffalo's right rear leg. The obverse die was abraded even more severely.
Here is another example from this die pair on the PCGS website. This PCGS example was graded MS-63, which will give you some idea of the extent of the die polishing. The thinking has been that the vertical line to the left of the mint mark was a die gouge from the die polishing.
Here is another example from this die pair on the PCGS website. This PCGS example was graded MS-63, which will give you some idea of the extent of the die polishing. The thinking has been that the vertical line to the left of the mint mark was a die gouge from the die polishing.