If I'm not mistaken, Rochelle Illinois is where Whitcombs were built. They have one on display at the Rochelle Railfan park, at the diamonds where the UP crosses the BNSF. I think they also have a small Whitcomb museum in town...maybe at the old factory site? You might want to try e-mailing the gift shop at the Rochelle website to see if they know who can help you:
[foxdir.net]
There is a Chamber of Commerce link at the bottom of the page where you might get guidance, too.
Hope this helps.