I'm also a great-grandchild of Cleveland and Theresa Levergne. My grandfather was Willis Gallien, and my Dad's name is Louis. Willis and his wife, Maylory Guillory, had several children; most are still living. I'm not sure if you guys still check this thread, but I'll be happy to give you their names so you can fill out that part of the family tree.
Keep me posted if you find out any more of our history.