I don't know how true this is... but it has been said that John Banner had accepted the role with several conditions:  That he held no actual German weapons or articles;. That his uniform be inaccurate and unkempt (which would never have been tolerated in reality);  And finally, that he play Schultz as a total baffoon.  This all to be an insult to Nazis.  The Krag was supposedly to meet his conditions.