The kit shows the inner wing to consist of the part where the nacelle fits as well as a small outer strip. If you do it their way, you will be in a mess of trouble.
My method is to remove most of the blanked area for the engine nacelle, leave small attached tabs to butt fit to the nacelle and to replace all of the inner ribs and structure. Just eliminate it all.
The ribs were traced over balsa wood and cut ( approx. 2 mm thick ). In addition, a whole new landing gear bay is cut and placed. All is glued in placed over the lower wing skin
for some reason, a crease developed over the leading edge. Oh well, no prize for me there.
trim the blanked nacelle outline
fold over and glue the upper wing skin.
More next.
Isaac