I have one yes/no column for successfule conversion to epub with metadata and covers
and another to keep track of converion problems such as page numbers, page headers, books that can or should only be pdf such as cookbooks etc. DRM
Thanks to Chaley for the custom columns as I have many ebooks and this makes the job a lot less confusing.
I like your idea of original source, but by now I have no idea on over 6000 books
Oh well something to think on for future