Got a note from a reader:
One very minor nit to pick: Callahan would still know his service number. If he said he didn't recall it, that would give Harlan Jones reason to question whether Callahan was who he said he was: no serviceman ever forgets his service number. And every other serviceman knows that; it's one of the ways we pick out the "Walts" out there.
Not sure what a Walt is, but I think I get the drift. Fixed.
Another fix was in city populations. At various points in the story I referred to the city and planetary populations. The other day I checked with Al and some of my numbers were wrong. I went through it again and fixed a few items. Fixed.