The Co-op 3 with a Chrysler 4.0L 6-cyl gasoline. 1936-1950
http://www.tractordata.com/farm-tractors/005/8/3/5839-co-op-3.html
Although Cockshutt made some Co-Op tractors like the E3, the No.3 was made by Duplex Machinery
in Battle Creek, Michigan, and South Saint Paul, Minnesota.