M&SC 107 is a double-end wood combine built by the Ottawa Car Company in 1912. Seating 32 passenmgers, the car is 49' 4" in length. It is narrow by most interurban standards since it was required to operate for a short distance along shared trackage with the Montreal streetcar system, as well as over the narrow confines of the Victoria Bridge.

When the Montreal & Southern Counties abandoned passenger service in 1956, #107 was donated to the Ontario Electric Railway Historical Association and is now in operation at the Halton County Radial Railway Museum in Milton, Ontario.