Kindle INDX specific details

Hi Guys/Gals,
I need some answers to some issues I am having with the mobi internals, so I thought I someone here might have some knowledge to impart.

I am importing azw3 files into a C# application and rendering the output. I can obtain and render the text and imagery fine however are having issues with obtaining the TOC/NCX.

Now I am aware you will probably point me to the python scripts that deal with this in KindleUnpack and/or Calibre (which I've done) however my python skills are really not up to scratch.:rolleyes:

I can understand to a certain extent what the code is doing and can parse and decrypt the mobi header, EXTH and INDX segments however at this point I'm unsure how the INDX describes the NCX and would appreciate something in English that would describe the process.

I've had a look through the code and was hoping someone could provide some pointers. A description of what each of the segments actually do would help e.g. IXDT, SKEL, FRAG and anything else related to the indices.

Any hints would be appreciated. :help:
Cheers

P.S. I have also spent far too much time examining the various wiki entries on related to this issue ...