Al, not only do they not match anyone on the front, in at least the case of this '57 panel the number of the card on the back is incorrect- in '57 #87 was Tom Gorman, not Clint Courtney, as it was on this panel (this one is not mine, it sold in the last Mile High)
The few salesman samples I have that I also have uncut production sheets for match up on the fronts, the backs are a completely new creation. I would suspect if you can find a 1st series sheet from '59 you'll see who is missing from Don's panel.