By following the plans slavishly I am finding that EITHER
The Wing ribs are to long OR the fuselage formers are to close together.
There seems to be almost a 1/8th to 3/16th difference between the wing chord width at the ribs f 1& 2 and the Position of formers b5 and b3. As the Central Wing panel doesn't FIT quite right in the hole made for it in the fuselage. I've probably built 6 of these over the last 20 years (Ive been building kits since i was 10-12) but Ive never quite gotten this right or the parts could conceivably be off but they match the drawing.