Thank you for those photo duplicate suggestions...that'll be next on my list, but my "people" issue still isn't resolved.
The library restore seemed to to something - it took hours and overnight for it to restore, so I was hoping it was identifying all the faces. However, I now have a few more names that I had identified a long time ago, but instead of saying it had scanned approx 3500 photos (I think done before the SDD to HDD move), it now says 0 photos have been scanned (even though there are more identified faces), and that when the app is not being used it will scan again.
I left the app open but not active (had finder or Safari open on top) overnight, and nothing had been scanned.
If I choose a name in the person section and ask it to search for more of that person, it immediately says no other photos with that person has been found.
While I have the "show face names" on, no circles or bar underneath faces in photos appear.
So confusing to me, hoping you have more ideas! Thanks.