I believe most Ontario Mumby can trace their roots to north Lincolnshire, and in particular, the general area of Brigg. My ancestors were also from that location. In the mid 18th. century there was a village in Ontario called Mumby's Mill. In NY State there is a Mumby's Rd., while in England there still exists the original village of Mumby, so named after its settlor, the Viking named Mund.