I think there are many files saved under MENU2, they are the ones which contain the main menu, SSE menu, title screen, and almost all the sub menus.
If ya don't have them, you can go here
http://www.smashboards.com/showthread.php?t=230551 and download the MENU2.rar And just to remember, you will need brawlbox, 'cos ash cannot extract those textures.