Thanks so kindly Greg!  You're always so helpful.
 
For ePub / mobi, etc.  is there a standard for italics & bolding?  Or do you translate everything into HTML?
 
What do you suggest the best way be to view the uninterpreted source so I can check out what to replace?

EPUB and MOBI formats _are_HTML, internally. If you want to examine the internals of an EPUB, just open the EPUB file with any ZIP/UNZIP app or program and you will see internal files and folders in it, with .html or .xhtml contents of the ebook chapters. EPUB file is simply a ZIP file with a different extension, and some standarized contents internally.
 
For MOBI it's not that simple, but @Voice converts it to EPUB anyway to read it. You could copy the converted EPUB file from @Voice eBooks folder, or use e.g. Calibre program on a computer to convert them to EPUB.
 
Greg