If the last opended one was on the boot drive...
Applications/Eudora Folder (Last file location opened)
/ (Path to that location)
(Name of file)
But if the last thing opened was not on the boot drive, NSNavLastRootDirectory is dropped & the whole path is in NSNavLastCurrentDirectory...
(Will have an additional field called altname with filename first, curiously followed by the full path including filename)
I can see no consequences of any upgrading.