ESRB_RATING.ptx appears to be DXT5(?) compressed with a size of 1152x676. They really considered the game having animated blood or was a mistake.
background.ptx is the same but I cannot get the proper image, luckily I got the size (Shift 15 may help).
I think I found a header at the bottom (cause Xbox Big Endian)
2bytes: 00 (start)
2bytes: Width (of source image before conversion? + 120 pixels)
2bytes: Height (of source image before conversion? + 120 pixels)
2bytes: Compressed texture format? (02 = ?, 04 = ?, 2A = ?, 3E = ?)
4bytes: 54201A (end)