@ Wurger 190 & KenHash,
I’ve never questioned the authenticity of my knife. My motivation to post here at BF was to possibly learn where the knife falls in the timeline of its history. There have been a number of iterations of the Tech. Blade steel was changed as well as location of production(I know mine was made in Seki)
Your knife is a SOG Tech 1 model S10. It first came with the rectangular nylon case that you have, then, later with V shaped sheath. That would make your knife one of the early ones circa 1990-92 or thereabouts. The two Tech 1 sheaths are as below. That yours is missing the white in the lettering is not, in my opinion significant, as these things happen in factory production.
The blade steel of your S10 is Aus6 made by Aichi Steel. It was marketed as 440A by SOG as it was a more familiar standard for the US market. The S10 and S12 are often confused because the S12 was originally introduced as the "Tech" with an SK5 blade which was later changed to Aus6. To my knowledge the S10 was never made in SK5, as I have never run across such a knife. I had one the SK5 S12 which came with with a leather sheath.
Both the Tech 1 and Tech 2 were manufactured by the Kinryu Corporation in Seki Japan, owned by the Suzuki familiy, who also made the Governments, Tigershark, Desert Dagger, Pentagon, NW Ranger, Seal 2000, Seal Pup and Recon Bowie for SOG.
SOG's production in Seki Japan ended in 2006/2007 and was moved to Taiwan.
The Tech 1 S10 and Tech II S12 were never made in Taiwan, only in Seki Japan.
SOG Specialties started in Santa Monica CA. The earliest nylon sheaths for models such as the S2 have "Santa Monica CA" on them. Somewhere around the time they moved to Edmonds WA they had some models with and without the location. Then the EDM WA became standard until SOG moved to Lynnwood WA.
Hope this helps.