ship.pps has a 2-part table, first part is sectorstart addresses, second part is file sizes.
multiply sectorstarts by 0x800 to get file locations. There is no nametable, and there's 9518 files inside.
Ship.pps and ship1.pps are the same file btw, if my memory serves me right, the game actually uses only ship1.pps and the other file can safely be removed, reducing the game's size by roughly 300 MB.
the files inside are largely identical to the ps2 version counterparts, however, i will warn you that porting over the ps2 script is not as easy as throwing the files in and calling it a day.
you will have to edit LOTS of the text files to make them work on the psp, othervise the game will just crash on you every 2 minutes.
also, it will look like this, so getting it to play nice takes some asm trickery with the text parser.
on a side note, since the game is running on mauritius engine (a korean hack of unreal engine for ps2), some things on it can be edited with a certain version of unreal editor, but if you attempt this, you will have to keep in mind file endianess and account for the console specific changes made to the file headers.