data_iz -> pic2d is where all the graphics for the top screen are stored, while data_iz -> pic3d is where all the graphics for the bottom screen are stored.
As for the menu and other things, you may want to check both folders... since I know they're separate for most of the time.
(I'm not really hacking the game myself, I'm actually just ripping images using Tinke, so I've been searching each packed files for them... though sometimes I forget where some things are.)