How m55 filesystem works

i am very interested in patching m55 for freeing as much space is possible.
i would like to use this thread to discuss this issue as technical as is possible
i succeed to understand some parts of the original patch, and the 256kb patch too, but i don't understand some things:
- so there are 2 types of tables - one of addresses - psysical one i guess
- one of refferences - logical ones
why in the second patch appears 51 to 55 in table of addresses?
why table of refferences begins with 80 02 - after that i see that it goes from 6 to 6 bytes
maybe somebody has a map for m55 phone
i had a version for chaos patch with comments in english - if anybody needs it, feel free to ask me for this

thanks