To quote Mart Twain, it's a difference of opinion that makes horse races, but I am quite comfortable in believing the wings were either sawn off an intact original body or made on the same tooling. We are just looking at pictures and I will claim some intuition from living with a JS II for decades but I would like to know why you think otherwise.
It really boils down to the presence of wood where it should be absent. There seems to be no evidence of screw holes where they should be for a pickguard, no evidence of holes from knobs, indicator tacks, and jack in their factory-correct locations and not enough round-over/bevel at the edges of the body. I suppose it's possible the mahogany wings were part of a factory body blank in its roughest form, having only been band-sawed out of the plank, but, at that point, I don't think you can really consider it a "Guild" part.