iPhoto pictures lost, then found - how to save them to hard drive
If you are fine with starting over with albums and face recognition, don't worry about the folder structure. The metadata on the photos (assuming they are JPEGs) will even give you back a lot of events. (iPhoto makes events automatically using the timestamps). 

I think face-recognition and keywords and ratings and all of that is going to be gone, but just save the image files you want to keep and forget about the rest.