If I could make a suggestion/request, I think this would be an excellent board for this challenge. The Eagle file already exists for the board and would only consume about 1 square inch of your PCB stock. With a $500 dollar reward, guys. I'd personally be satisfied with just the top of the board, since A. Zach posted this bounty for the sake of verifying the X-Carve's ability to mill PCB precisely, and B. Setting up and milling two sided PCB wasn't included in Zach's scope of work for this challenge and, I personally believe, it'd be a whole second tip jar bounty's worth of work explaining that.
The deets on that board are below:
Breakout board for FTDI FT232R chip, a USB to serial converter IC. The IC is a 28 SSOP package with 0.65mm pitch and 0.3mm leg width. This does mean that the cut between each solder pad would need to be no greater than 0.35mm wide, but that shouldn't be an issue with some of Inventable's 0.1mm diameter PCB milling bits.
Thanks again, Zach. Hopefully someone picks this bounty up.