That's what I'm leaning towards too Fab. Some custom job. Great workmanship on it from what I can see in the pics.

As to how to mount the wings on it, how tight is that biscut in the wings? If the fit is snug you could most likely get away with running a strip of electrical tape over the areas where they meet the fuselage. If the biscut is a little loose you could build it up with some CA until they're snugged up. If you go to Home Depots' electrical department you can even get yellow tape to match the color.