Thanks as always for posting these, Leon. I see that the last letter is from Howard Leheup. I posted Lionel Carter's obituary of him here:
http://net54baseball.com/showthread.php?t=221758
And as for the second to last letter, I have the 1959 Sport Fan Who's Who (two copies of it, actually), and I think I remember seeing John Wagner in it, but I'll have to check later to be sure. I posted the entire 1958 Who's Who here:
http://net54baseball.com/showthread.php?t=222091