transfer music art from Music Desktop App to the Music file

I got tons of very rare Music files. Some of them ripped from vinyl. I added the album cover using the "info" function into Apple Music. Music embedds this picture to the file (mp3 tag). Unfortunatly I used also the very handish function of Music "get album artwork" Now over the time I end up with a mix of pictures ether added by the Music Application or added by me. We talking about several TB of files. The problem starts by doing backups of the Music library. The backup contains only album art embedded in the Music file since the automatic added pictures stay in the folder ~/Library/Containers/com.apple.AMPArtworkAgent/Data/Documents/artwork. Those file cannot be assigned easly by the user. I guess that's done by the sqlite DB in ~/Library/Containers/com.apple.AMPArtworkAgent/Data/Documents.

My question: Is there a way to extract the pictures from Music Desktop Application and save them to the Music file? If not maybe soomebody with the same problem has already written a well working script?

To say it right away: In case of a restore from backup I could just use the function "get album artwork" again and the picture gaps are filled. Believe me it's not that simple with such a huge Library, especially if you have more then one audio system and some of them are high-end systems which are fed with high resolution files.