What would you like to be changed on the back?
- Clean up logos (I agree)
- Change rear text font
You don't have to change the font if you tend to keep the white box in the background but retyping it to improve the quality would not go amiss.
I'll anyway retype the text as I prefer white text without any extra stuff (like the white box) in the background.
I can provide you with raw scans of Tetris Battle Gaiden in addition to scans of the manual (which has pictures of the cast). Does that help?
How does this relate to World League Soccer?

I too have the box and manual of the Tetris Battle Gaiden that I can scan (I might have do that already).