Each .PAK file comes with an included .TBL file, which I'm pretty sure includes some if not all of the needed information about the file sizes and locations in the relevant .PAK file. Problem is, I'm not able to figure out how to actually extract the .PAK files (let alone attempt to repack them.)
Here's the headers for one pair of files.
psvsys.tbl

psvsys.pkg

Download for two pairs of files.
http://www.mediafire.com/file/7cu8t12zr ... G00940.rar
Includes:
1. psvscr.tbl/pak (Game scripts)
2. psvsys.tbl/pak (System files)
PCSG00940
