there are .SPK (Singlepack?) files with one file inside and .MPK (Multipack?) with multiple files inside
i used offzip -a with standart settings first on a .MPK file and got multiple smaller zlibbed chunks... each of therse chunks then contains an amount of files (1 byte in the archive = number of files) after that follows the filetable and after that the raw data.
i hope this can be automated easily cause unpacking and unpacking again is highly annoying
i don't have example archives right now(maybe someone else can upload some?

