I can highly recommend 3 vendors for the most authentic tobacco flavors to me:
nhaler: Plain Tobacco (lighter) and Cigarillo (full flavor). These are listed under the High Voltage Octane Liquids. He has Octane, regular High Voltage, and Lung juice. The Octanes are very authentic. I love full flavors so Cigarillo is my favorite. But I also vape Plain Tobacco as well.
Vapor Station: From lighter to full flavor: Tennessee, Texas, and Tampa. Tampa is my favorite as it is full flavor tobacco and very authentic. If you like menthol, I've read that Seattle is the most authentic menthol. Their Frost is minty, but Seattle gets the best menthol from reviewers.
Halo: People most prefer Halo Freedom, me included. Very authentic, slight denseness or heavier rounded feel. Great Vapor! and very subtle cedar-ish undertone. Very nice vape and I like this after dinner especially.
I'm not just recommending them. I love these. I searched and purchased more juice than I would ever admit to, in search of "the" authentic tobacco. I found it in what I've described above and I will say with all truthfulness that I use Cigarillo, Plain Tobacco, Tampa, and Halo Freedom all day, everyday. I've done the leg work for you. Save your money and start with the best. I'm one of many here that have "kissed a lot of juice frogs until we found the juice prince". If you like light flavor go with Plain Tobacco, Tennessee and/or Texas, and definitely Halo Freedom also.
Good Luck in your search and Happy Vaping. Please post your findings in the Liquid Review section on the forum.