I have toured the plant 3 times in the last 7 years. The plant personnal were more than excited to give tours of the plant when I went through. It was a very good tour with the Gleaner portion coming last. Call 620-327-6300 which is direct to the Hesston plant, this should be the right number, if not, try 770-813-9200 in Duluth and someone should be able to hook you up. I did not get free lunch, but lots of pens, keyrings and notepads. Good luck.
If you need to stay overnight while there, there is a nice Americinn on east side of town.