This tool allows you to extract graphics in "Battletoads & Double Dragon - The Ultimate Team.nes", and then easily reinsert it. This tool was partially tested so use it with discretion.
Synopsis:
btdd2bin.py [-d | -c] --decompress --compress
The rom must be "Battletoads & Double Dragon - The Ultimate Team.nes" CR-32: CEB65B06, rename the rom or change in line 116.
Of course, there's no need to ask. Feel free to use it in your project. I only ask that you mention me as contributor.