I promised I would document the journey, and so I will.
Introduction and Acknowledgements:
Much thanks to Dorkvader, who suffered my ignorance.
Soarer, who came up with the firmware for me to get started.
So... what's the big deal about the left-handed ergo? For starters, I wanted to get an orbweaver for a long time, but never got round to it because I don't merely game on it but Dota 2 requires a significant amount of typing, like "Stay in the trees!" or "Don't cross the River F@g!" (the river's name is f@g), and so on.
With the Ergodox, however, I can make it what I want it to be, and so I am going to make it what I want it to be.
My interest was initially piqued when I saw that it is possible to invert the design being printed on the PCB. I thought to myself, I can just wire everything in reverse and hope for the best. Reality, however wasn't so kind and I had to go through quite the number of speed bumps before it is finished. The physical aspect:
1. Diodes should be soldered the right way in (line on diode to square pad). Doing it the other way around is possible, and you'll just have to use the other keymap file. I find the best way to do this is to have a small blob on the square pad to start, then putting the SMD diode on while melting that small patch and finally soldering the other side on as normal.
2. No LED support yet. I don't plan on adding LED support any time soon, so you don't have to solder the LEDs. It's easily done later.
3. Desolder the teensy board from the pinouts, and then solder it on in reverse. Make sure you have enough clearance to be able to press the teensy button.
4. My USB type-B plug came with a broken pin. In my haste to get the keyboard running, I just used a direct connection to the teensy board.
5. Scroll down or click this link for help on how to load up the firmware:
http://geekhack.org/index.php?topic=59068.msg1353525#msg13535256. Solder everything else on according to the massdrop instructions and you should be fine.