Thank you for your contributions. I posted for details to do exactly this a few days ago : (Resolved) Restore V12 from V10 backups
The solutions offerred both here and in my linked post might work fine for the database backups. However, I backed up using ‘…backup …–with files’ option, resulting in files.tar and private-files.tar files.
How do restore the files from version 10 to 11?