This is a very foggy area for me, so I am in no way an authority and I'm certain there are very, very few people who would.
I can say with near certainty that this is not a SOG knife (or a SOG that is a "mainline" knife...meaning a knife promoted by SOG's international headquarters). It could be a fake SOG, though most fakes are replicas of existing SOG models.
If you didn't know, SOG uses "manufacturing" companies to make their stuff. SOG will assemble some of their knives/tool on-site.
That being said, I have seen/heard of these manufacturing companies making some knives that are not "official" productions (meaning promoted from SOG's international headquarters). I'm uncertain as to whether these knives are prototypes, limited productions, or knives made for "other markets." I have seen them and I have seen them in Japanese magazines or on their covers. I'm nearly certain that these knives are not of Spencer's design, rather likely from someone at the manufacturing company.
It might be a special arrangement the manufacturing companies have with SOG that they get to produce a little something for other markets.
But as I said in my opening statement......I just don't know for certain.