Curiosity is driving me crazy, please help.

This is a plaque I bought from an elderly lady, unfortunately I had it in my trunk hoping I could find someone who could give me some info about it and I was in an accident. Sadly it has bad damage to it but the I'm still interested in knowing about it. The lady I bought it from told me that this hung in a "secret society" club that her great grandfather, grandfather and father belonged to. It was upstairs in a building in Main Street of Sauk Center, Mn. I think it has something to do with the Canterbury Tales. Please, if anybody could help me I would appreciate it. The plaque measures 45" long and 17" tall. I believe its plaster but the back is carved out and has some coating on it.