Sorting edited versus non-edited images

Hi,

I'm working through horribly-unorganized iphoto and aperture libraries on three computers, trying to create one "master" library that contains all of my images (probably around 22,000 different images in all). I've found a good way to combine the iphoto libraries but not a terribly efficient way to bringing the aperture images into iphoto (that's where my master library will reside).

What I finally settled on was to export the RAW images from aperture into a folder, then import to iphoto. That works great, but then I lose all of my post-processing. I haven't worked on all the images, so I thought it would be great to make a folder with just the edited images, then export those to iphoto. But I can't figure out how to separate the edited from the non-edited images. There may be a completely simple way to do this, but I just can't find it.

Can anyone provide advice on how to distinguish/separate edited images from those that haven't been touched? In large quantity, so I can't just flip through image-by-image to figure it out. Help is greatly appreciated. (And for all future work, I promise to keep things better organized! 22,000 images snuck up on me quickly!)

Thanks,

Janine