^^^ --- This thing, right? Well! I can understand why you said it was your old guess, if not your current one still. Fairly interesting design! An issue with it though is that, I think, its based off the FT-series of tanks, which would make it based off French designs. I think and argument can be made however that the US would try to make a light-tank series inspired by the FT --- perhaps they captured imported models on the frontline while fighting Confederates equipped with French-imported FT tanks, reverse engineered the design, and made something like the 3-Ton. Its not a bad idea though. Hell, I bet Custer would absolutely love the idea of a smaller, faster barrel.