Hello Gap and Wise,
there are two models in the Pack 3D Models collection, from different games. One is a reasonably well looking low-poly version but offerend only in 3ds (Wise, can you take care of that? I do not use 3Dmax ...):
http://p3dm.ru/files/37_grumman-f4f-wildcat-.html
By the way, converting of Sketch-up models often results in numerous fragmented and duplicated triangles. Same problem is also with Flight Simulator models (if I remember right, Sergbuto's Wildcat was converted from Flight Simulator).
Due to these nightmarisch problems I gave up on expanding my personal SH3 world by converting models.
Cheers