Thanks for the suggestions. All I needed was to get my mind opened up a little bit. And writing did that. I noticed a shallow groove on the inside of the Dia Compe calipers, that wouldn't allow the pads to slide all the way down in the slots. So I changed out the pads, and for good measure filed the slots a mm or so too. That gizmo from Ben's Cycle looks the schizz. I might just get one just to have around. In this ongoing saga--Sunday afternoons--I put down my 8mm wrench a couple weeks ago and never saw it again. This same occurrence befell my Park Tool needle nose pliers over a year ago. I recently bit the bullet and bought my third pair. The first grew legs and walked away. I was able to make use of the dumbbell wrench I inherited from my dad, for those 8mm nuts on the brake pads.
If you all are lucky you will live to be old and forgetful like I am. It's no fun to be constantly losing things. All of today's tools are accounted for. Barely. There was a moment of angst when the 10mm couldn't be found, briefly.