I think the 1956 is one of the tougher ones. There's a great thread on samples, in general here:
http://www.net54baseball.com/showthread.php?t=132990
Anthony Nex is one of the foremost hobby experts on such. Plus he's good peeps.
Even this great overview of the 1950s Topps samples lacks a 1956 scan:
http://toppsarchives.blogspot.com/se...%27s%20Samples