I used the stack of washers in the background to pull the splines out of the bushing so I could set the lever back to its mark, and tighten down the nut. The truck went back together quickly after that, and the clutch is back in the middle of the pedal, where it belongs.
If it wasn't, the lever
E7TZ-7A554-A would need to be replaced, and installed properly (since that's how the pedal is adjusted). This explains why & how to check the lever:
Finding the right washers is probably the hardest part of making my own bushing. But I have an extensive junkpile...