The question "Why do I have many duplicate files after importing a backup into Apple Aperture?" was put on hold as "unclear what you're asking". I don't know if it was later edited or if other readers just didn't understand, but the question is in the last sentence. The OP wrote:
So my question is: has anyone else had this problem, and are there any ideas on how to recover the photos in the Aperture Library without using Aperture or Photos?
I happen to know the answer and would really like to help this person, but am unable to. I don't have enough rep to cast a re-open vote, so I'm suggesting that other higher rep users please do so, if you're able.