Apple Music Library Not Showing Songs

I can no longer see any of my CD-Ripped Apple Music files (and no, I don't want a subscription to Apple Music!)

1. I restored into Apple Music my library of music from a backup into the latest Music App (Sonoma 14.2.1, Music App 1.4.2) - this is all working fine and includes all of my old tracks and iTunes Store purchases and they all play.
2. I next went to sync my library over to my new iPhone - currently the iPhone only has iTunes Store purchases on it and has NEVER been sync'd with any Music Library (I've just downloaded purchases on to it)
3. I went to the "Music" tab in the Sync Window, Selected "Sync Music onto <iPhone>", Selected "Entire Music Library" and hit "Apply"
4. I got a dialog that says: "Syncing <iPhone> with this Mac will replace media from another Library on <Name of Old Mac>" "iPhone can only sync with 1 computer at a time"
5. the <Old Mac> in question is nearly 10 years ago, and this iPhone has NEVER been plugged into it. I don't even have that Mac any more!!!!
6. I hit "Sync and Replace" button - I am afterall sync'ing the iPhone to my Mac right - but it syncs my iPhone library to my Music Appl library!!!!

Ok, Now:

(1) The iPhone has exactly what it had on it before

(2) The Mac's Music App now ONLY sees the iTunes Purchases, it does not see ANY of the music Files I have in my Media folder

(3) All of the Music files I want to use are still there, but they no longer show up in the Music App, and I cannot get the Music App to even see these files anymore. I have reset the Settings/Files location, I have tried to start a new library and reset the files, etc, but nothing works now to have the Music App recognise any of the files. And of course, the iPhone is unchanged!

Thanks for any help.

William

PS - I guess I can just go through all of the copy to an external disk, reset from that disk, etc that I have done already to get the Library to show up in the Music App, but that still doesn't show me how I can transfer my Music to my iPhone - which is a legitimate use of my Music!