Since version 2.09, the default sounds are replaced by a sounds.res file in the game install folder and a token file in the Sounds folder.
But, if Im not mistaken, you can just add a Ju87 folder to your (empty) sounds folder, put the wind.wav file in there and the game will use it.
I might be off here, but i think that the game will use default for any plane/file it doesnt find in the SOUNDS folder...