[edit] There's one but... The .zon file needs to be corrected as well. Moving the visual object (3D model) requires the SH3ZonesCtrl to be swapped as well. I think the easiest way to do this is by swapping the parent id's between the two controllers that are linked to the props. Also, I have no idea what the effect of a broken prop is (iow. the wrong prop may be broken). I suggest one of you tests this out before making this change across all submarines...
That, or investigate other (better?) ways of changing rotation direction... I have no other ideas though...