"The thing is, if the GOP and the Bush campaign was tied in anyway to getting this other side of the story out, then it would be a PR/media disaster. It would be portrayed as 'Bush the possible deserter' versus the war hero."
That effect might be blunted a bit if they just spoke out in support of Bush and refrained from attacking Kerry (at the convention). Also, just their appearance there amongst the other veterans would have an impact, as long as they were identified by the media.
I definitely agree that Bush should surround himself with as many veterans as possible. And if he can do so with some who served with Kerry, then all the better. So there I think you're absolutely right.
But I don't think the mainstream media will in anyway give any attention or credence to what appears to be the majority view of those who actually served with Kerry. Of course with the internet and talk radio the message can still be sent, but despite their decreasing importance the fact remains that the broadcast networks still reach many more people than any other single outlet, including the cable nets.