Thanks to you as well as a few palm documentation files from 2001 (and lots of use of a hex editor, ultraedit) I managed to make some prototype C# code that reads out all the raw HTML content. To share with you some information, if you like, it is actually list this:
Palm record index
MOBI header (Kind of obvious)
EXTH header (A dictionary format set of information about the book)
FLIS header (license information)
FCIS header (images information)
I remain unsure on how to determine where the images start and how long they are. Nor do I know the 2 byte record between content & images nor the 4 byte one at the end. Maybe some sort of checksum.