Funny, I'm not a scale nut by any means, but the guys at Multiplex sure must have a sense of humor.
The nose is sorta from a SuperCub, with the wide mouth. But, they stuck the engine cylinders out the side like a J-3
The stripes are a cross between a Super Cub and a J-3. Not sure what the rear window is supposed to be from? No struts or spats (which doesn't really bother me).
The N2020M is from a real J-3: http://www.airport-data.com/aircraft/N2020M.html