I believe that Joe Johnston, in his spare time back in '77, did do a series of cutaway / technical views on the X-wing. I think it was done as an aside from the production of the FX on STAR WARS - maybe even for martketing purposes. Since that kind of info isn't really needed to get the FX on film, it probably had no bearing. But since it was done by the FX illustrator on the film, that's good enough for me. Don't know if these guys used that as a reference or not.
The interior details appear to be based on the "Incredible
Cross Sections" book, which followed the Johnston drawing.
I'm really looking forward to this kit.