I think you're going to need magic in stead of clever image enhancement software.
Although, what Fluke did with his digital scope and enhancing software on a Belgian coin from edduns was nearly magic (https://en.numista.com/forum/topic47065.html).
But I guess you have to send him the coin to do his thing.
It seems like a 7 and then you can narrow your search down to 1870 or 1871. And after the 7 it looks a 0 and then it is 1870. But to be honoust, if it was my coin, I'm not sure enough to really decide it's a 1870. And I played with contrast, brightness and negative image but this was the best I could find.
The only problem is the 7 and 0 seems so close. I have the 1870 myself somewhere, so I have to check if the digits are indeed so close to each other.
I agree with Muygrandeoso & Prof that it could be 1870, having stared at it long enough there appears to be a 7 directly at 6 o'clock and the 0 is quite visible with a good space between the 2 numbers.
I could always be seeing " things " though
I deny nothing but doubt everything, opinions are made to be changed, how else is the truth to be gotten at.
Thanks, everyone, I'm going to put it down as 1870 as a best guess. I think I can see the 0, too, and clearly there is part of a straight line where the 3rd digit goes.