Looking for Documentation for a Story About Walter Grombacher

Hi,

Richard Verber, a Senior Master from Chicago, wrote in 1986 that a Chicago player once let a live chicken loose in a Milwaukee chess tournament. I have never been able to document this.

However, I just found an essay on chess and mental health by Tim Redman, a former USCF President, that the player was Walter Grombacher and the tournament was the Western Open.

Can anyone provide documentation for the year in which this occurred?  I have checked the crosstables of this tournament and found that Grombacher played in it from 1957-1960.  However, I have npt found anything about this incident in the newspaper accounts or the chess magazines of the day.

Does anyone have the Illinois Chess Bulletin from these years? Perhaps something about it is in there.

Thanks in advance for any help.