In this article, Wargaming posts - strangely enough - the history of T28 "Prototype". Just to be absolutely clear - this vehicle is a fake, made up by Wargaming to fill a slot that would otherwise be empty, preventing the full branch creation. In fact, blueprints - were made, but not by American engineers, but by SerB's design bureau.
This doesn't come by surprise as WoT Blitz is getting same branches as the PC version and along with it the fakes too. To be honest they don't really bother me except when Wargaming pulls the "realistic" and "Historical" accuracy cards to nerf/buff certain tanks, that makes me frown.
You can check here many other tanks that are actually fakes or wrongly named: http://ftr.wot-news.com/2014/01/07/its-a-fake-part-2-wargaming-fakes/