rambeau

I have several photos of what have been identified as "old Mack logging trucks". They are chain drives (the drive is visible on the side), no top, solid rubber tire, and a logo on the grill that looks like an "M" in a circle. Sound like a Mack? If so, what probably year? 1916 has been suggested, but I don't know what else to look for to pin it down. Thanks for any suggestions.