Robn1, been off this a while but got chewing it again after seeing Ep. VII & the First Order 2-seater TIES (and thinking "those must be larger to hold two crew - but how much?") However, I think you meant the AMT kit 'wings' are too narrow. Checking various sources here & elsewhere, it appears that the height x width proportions are off by about 4% (3.22% actually) on the width. This difference, while subtle, would be difficult to correct by simply splicing in extensions to the panel and 'rib' detail. The panel pattern is perpendicular to the edges, so changing the side angles would require removing and altering not only the panel sizes but also the pattern orientation, hence full removal & replacement. But! Since only one altered panel master would be needed, cast 4 times, or one complete side, cast twice, I might actually attempt it. However, we're talking about about an 0.1588 inch total width increase, or roughly 5/32nds. That would be tough to pull off using traditional means.
Still, less than 4% doesn't really rate a label of 'wretched & completely wrong' by my accounting... and perhaps not really worth the effort. Perhaps there is another problem not yet identified?
Regards, Robert