There are 25 different 1868 (with reverse of '68) DDOs catalogued. They are hard enough to attribute on high grade coins. I wouldn't attempt it from photos on a low grade coin.
The 1868 TDO is a possible attribution for this coin. The engraved leaf and the date position seem to match. I can't tell from the photos if the reverse is a match. The degraded surfaces of this coin make attribution very difficult, especially from photos.
As far as using SNV, it runs on Windows, Mac and Linux. It is true that the downloadable file on the website is Windows only, but that's a demo version which would not help you attribute this coin.