+1 A serious C & V owner/hoarder is going to buy a $10 digital caliper. Too many oddball sizes out there. Its one of the first tools to buy for the tool kit IMHO.

Six speed brought on the 126mm spacing. Exception: Suntour made an "Ultra six" freewheel, that had five speed spacing. Even some early 5 speed bikes had 126mm (if I recall correctly). I think my 1973 World Voyageur came with 126mm spacing. That's pretty early for 126.

Answer to below: "D"

Do it again. Verify everything (# of bearings, condition of cones and cups, etc.) Use an axle vise to keep your axle from rotating. The difference between loose to too tight can be just a few degrees. I use a clock face analogy when tightening cones. Cone is at 5 O'clock: too loose. Tighten to 6 O'clock, too tight; back off to 5:30, just right. Realize the QR will tighten it up some once you mount the wheel, so it needs to be ever so slightly loose.

Quote: Here's my Stupid Question:

Yesterday while cleaning, re-greasing, and reassembly of a Shimano rear hub (7 speed Hyperglide freebody), I could never get the axle adjusted correctly. Either too much play up and down (more on the nondrive side and even then the friction has still bad), or too much friction, and the axle would barely spin.

a) the hub is shot, toss the wheel
b) the cone(s) are shot, find new cones
c) both a) & b), again, toss the wheel
d) mechanics error, try, and try again