Welcome to the forum oldturkey!
We haven't toured the factory, so I can't offer first-hand info, but I did find the following:
According to this web page, Keystone tours are Tues-Thurs... there's also an address & ph # listed. http://www.amishcountry.org/group/keystone-rv-company
More info for the area: http://www.amishcountry.org/rv-travel/factory-tours
From Keystone website: [contact page] (574) 535-2100
Switchboard Hours: (Eastern Standard Time) Monday-Thursday 8:00 AM - 5:00 PM Friday 8:00 AM - 3:00 PM
Happy trails to you & yours,
Terri, the Chevy co-pilot