The name of this film is Hunted in Holland (1961):
http://www.imdb.com/title/tt0167613/
It wasn't shown during the Festival, but it was definitely a Children's Film Foundation presentation, as you mentioned in your email. You can buy it and several other CFF films from Ebay and from this site:
Yes! This is it. I'm so happy. Thank you very much! I will definitely be ordering from that website all of the movies that I can. I just wish there was a way to get Adventure in the Hopfields. These two movies, and The Johnstown Monster were my 3 favorites. Thank you again!!!