Full and complete success!
It's taken another few days but I got it. I'm slow as molasses and get perplexed easily at this kind of stuff, but I'm persistent and I did it! I got an .annot file to re-install into a formerly deleted book and all my highlight and notes to show back up again! I feel like a tech genius now.
It's going to be slow and steady work getting all my books and notes back, but it's worth it and now I can, and from what I thought at the beginning, I'm amazed that I've found ALL of my notes and when I'm done it will be as though nothing had happened!
Thanks for everyone who took the time to read my long posts and try to help me in this thread!
And another big thanks to elminster who gave me the answer to recovering all the .annot files in the thread I linked in my last post. It was complicated and garbled looking to my eyes and the first many tries I kept getting something wrong or not understanding it right and it wouldn't work, but finally with patience I got it right.