Ugh! I feel your pain
I might take a slightly altered path here. I would likely open each session and start by soloing each track to ID what it is and rename each track. Then arrange them as works for me(or you) and then immediately go File>Save Session Copy>give it a new name and copy all the audio(really just a variation of what has been suggested). At the very least, If I didn't save a completely new session, I would go File>Save As and give it a new name