My crappy 1024x768 "hack"
So, I wasted a few minutes in Photoshop resizing the 640x480 backdrops to 1024x768. I could've spent more time on prettifying it and adding detail, but I was desperate to play CC and smash enemy green clones into little bits bwahahahaha. It's a little ugly, but tolerable, and it works. Extract these to the Cortex Command folder and it should all go into the right place and hey presto. Obviously CC has to be set to 1024x768.
Hope this helps someone else who can't stand 640x480
Edit: Forgot to add, for build 14. Yay.
Double edit: I am a retard and forgot to add one of the bmps to the actual file. Also now a zip for anyone who is allergic to rars.