I'm happy to hear that you made contact with the State Historical Society. Please contact the Waukesha County Historical Society Research facility as well--it may save you lots of time--one never knows. Remember the Industrial School for Boys was located right in Waukesha and the Historical Society carries many local records.
Also, just a reminder--Monroe isn't anywhere near Waukesha County. A good hour drive at 55mph.
Another thought--if your father was in the Industrial School for Boys around 1917, have you searched the 1920 Wisconsin Census? Waukesha County? Soundex? In earlier census, all orphanages, jails, houses of prostition, mental hospitals, were listed along with inmates. The 1900 census is especially interesting to look at for these. If you want to see what I mean go to the 1900 census and look up Elizabeth Schaefer in the soundex. You will find her listed in Milwaukee County in a house of prostition, located in downtown Milwaukee, along with the "other girls" , their private physician, and all private information about them. Jails also list inmates full names.
I would suggest looking at the 1920 census or earlier, just to see where your father was at the time.