Restore iPhone from old backup in Time Machine

Is there any way to restore an iPhone from an old iPhone backup that lives on a Time Machine external drive (that was a Time Machine drive for an older Mac that I no longer have)? I understand that the backups live in the folder:

~/Library/Application Support/MobileSync/Backup/

But I don't have a MobileSync folder in the 'Application Support' folder (using a backup from September 2012).

Any help would be appreciated - thanks!