That looks like a nice FS model. It's a big plane but I somehow doubt this claim is true. "The AT-802 series is the world's largest single engine aircraft". For example: the An-2 has a longer wing span & that's a biplane.
http://www.airliners.net/open.file/387938/M/ Theres an Air tractor at Tupelo. They share many similarities the landing gear struts are differant, but they both have many more simmilarities.