Many of the family have tried to research this.
We get similar result to what you have found.
Story I hear -three brothers came down from french-canada looking for cattle. They got in argument and went their separate ways. Brothers names Ora, Joeseph, Lawson.
My Mom's name was Elizabeth Caulder Mumbulo-married William Mumbulo 1949.
I don't know if you are still interested - reply or send email to firstname.lastname@example.org
and I can give you more info and contacts.