Zooming in on the 1st photo, the date looks like 1876. Comparing the first "8" with the last digit, there are 2 differences. 1. The first "8" looks rounded as expected while the last digit is more boxy. 2. There appears to be an opening on the right side of the last digit, like a "6". Thing is, the last digit appears to be about 2/3rds the size, so I'm not sure if it has worn off, the photo, or my eyesight. Hopefully a coin person will jump on here and ID.
Looking at a picture of an 1876 IHP (left) shows the top of the "6" to be rounded to. Plus the opening on the right side looks too small. Looking at all years (1870-79) the only year with a flat top and opening on the right side is 1875 (right).