Tiger Woods PGA Tour 2002 (PS2) - compressed "Rdat" chunks

[tbmq008]

hey.

so, i'm trying to write up a script that extracts assets from most of the files from the PS2 version of Tiger Woods PGA Tour 2002.
said files follow this chunked data structure where a lot of stuff within the file is split into "parts" so the game may load an asset based on just one part or many of them depending on how large an asset is.
but the thing is, some parts contain compressed data and they go by the "Rdat" name. i've been trying to cover these compressed parts all day and although i believe i "nailed" the details that would come closer to a "decompressor" of sorts i'm still not fully versed into how it works.

what i'm saying is i need help to properly finish the decompressor. most of the script's contents contain decompression code and it's all pretty unoptimized, not to mention it's a barebones effort for all the time i've invested in this kind of stuff.
in any case, here's the script. be warned though that it's WIP so expect the script "not working" the moment you get to use it.
sample files are here if anyone wants to do anything useful with it.