Originally Posted by
gthomson
I have a decently thin adjustable wrench which I sized correctly for the headset locknut and gingerly tightened it.
That's not how you do it. Read my post again. Study how to adjust a headset. You basically need to lock two "nuts" together on any system like this (whether it be a headset, hub, pedal, or bottom bracket). Or you can just hope for the best and maybe replace the headset later when it fails.