Completed the LEFT position and strobe lights. The soldering went quite well.
I tested the position lights with a 9v battery, per the instructions, and they all worked! But when I tested the white strobe lights, none of them worked. They don't even work individually on the 9v battery. I emailed Paul at FlyLEDs to see if he can tell me what's up.
Update: turns out I had a bad battery. It had enough juice to light up the small LEDs, but not the white ones. Switching to a 9v battery, everything checked out!