OK, moved stuff around. Do us a favor and print out a paper copy to test out button locations, distance from joystick, etc. I didn't design any ergonomics in this, and we should make sure it is usable as a control panel!
Also we may need to make the ring around the trackball larger if we want to see white around the TB bezel. Or it may not matter that much.
Also also, I made the button text smaller, but if you prefer original size we can just keep B1, B2 and B3.
The .jpg is so you can see it here in the forums. The .pdf is for easy printing. The .zip is the zipped version of the vector file. Most likely either the PDF or SVG file will work for final output.
Let me know if you need more changes!