Hi PeterT and JohnnyBook,
Thanks for the replies. I ran a few tests with Edit Metadata and you're right. The original folders along with all superfluous content like spare covers were deleted.
Apparently, I was just lucky in the past and did not change author/title before cover tweaking was completed. As usual, a case of operator error, not Calibre error.
Even on a clear day ... the memory can be a bit foggy.
Kudos to both of you ...
Marty