I recently posted about finally finding a workflow to properly convert a cache of old Doc Savage books to ePub files.
In the last installment, I used Calibre to convert the original BBeB format (Sony) files into rich text files. Then I was using Nisus Writer Pro to clean them up, and then finally copy the text to Apple Pages for the final tweaks.
This was workable, but I learned a few things, and improved my processes: