I was careful, but not careful enough. Had to back up and make sure I was building the LEFT wing and not the right, glad I caught early - it would have been a bit embarrasing to get further.
Not a big deal and was pretty easy to fix, only ego bruised...
Next is attaching the wing tip to the LEFT wing...
Saturday is my faux Check Ride with Robert, so I've been studying - we'll see if its "enough"...