AJ - thank you! I do appreciate the thoroughly described process, and I think you're onto it. I'm hoping for plan A, but thinking it might be plan B.
I've already over-shifted the 1-2 slider towards 2nd gear, and of course without the clutch released, I can't rotate the gears at all. I guess I'll need a helper, or a stick just the right size! And yes, it is a huge pain to get the slider back in the neutral position. I was able to get my fingers on the key in front and the key up over the top-side of the gears, but needed a large allen wrench to shove the third one in while I pushed the slider back. (Somehow I got it done while being able to see NOTHING because my hands were in the way!)
I was pretty careful during the assembly process, but it never occurred to me to treat the gears' brake cones. Makes perfect sense the way you described it. Of course I don't have a lathe, so I'll need to do these by hand. Based on this bit of knowledge, and the behavior of the trans, it seems like the first gear cone might be biased towards upshifting. (Here I am, trying to do transmission math in my head again!)
