Ok guys, thank you for the slap in the face
Actually, at this very minute, I don't really care about loosing the DB as I did not put the full collection under Calibre management
Having said this, whenever I notice a typo in the file name, I must corrected. Fullstop
I've been again and again searched the various menus, but did not find how to rename a book (read file name) from within Calibre
Any pointer would be MUCH appreciated
Second question: with time, I will be adding new FILES to the library directory tree and I will be wanting to do a full refresh
Again, how do I do this without loosing the metadata updates already done and without duplicating everything, "as per the rules"
Thanks!