<<Disclaimer: Verify this information before applying it to your situation.>>

A popular school fundraiser here in the Midwest U.S. (and possibly other
parts of the country) is "Market Day".  They have a website
http://www.marketday.com where you can find ingredient lists for all
their products.  The lists contain some of the usual ambiguities, but the
website also gives an e-mail address you can contact to get more
detailed info.  I used it to find out about their American cheese and was
told it is GF.