I am looking at purchasing a partially completed Series 7 Super Sport kit, which has had very little work done to date. Is it possible to upgrade the SS7 kit to an STi version by purchasing the individual STi kits listed on the Kitfox site? The list of "included kits" are as follows:

S7 STi Fuselage Kit
S7 STi Wing Kit
S7 STi Landing Gear Kit
Covering Kit and Rib Lacing Kit

Because the Fuselage Kit is listed, I'm wondering if the fuselages differ between the two models to the point that an upgrade is not possible. For example, the STi wing has larger chord, which raises a concern that there could be a difference where those wings attach to the fuselage. Is the landing gear different enough to raise concerns? What else is there that might/will cause trouble?

Has anyone done this, and if so, could you share your experience?