I have owned a few early Cockshutt tractors, most recently a 18-28, early 70 std, 60 std, late 70 std, and still have a 60 rc.  From what I have seen, the color change appears to have happened in late 1938, shortly after the style change on the 70 tractors.  The 1939 and late 1938 models that I have seen were red.  The orange wheel color information I have had has come from owning several early Cockshutt tractors, as well as discussions with members of the Cockshutt club regarding their restorations. The ones that I have owned were definitely orange.  I have not ever seen an early green Cockshutt tractor with red wheels.  I was told that the orange color was used to differentiate between the Oliver and Cockshutt tractors, and still use paint colors on hand at the time.  As for the decals, the ones that I have believed to be correct for the early tractors did not have the maple leaf.  I had to have the ones made that I used for the early tractors.  As near as I could tell from what was left of old decals before restoration, the looked the same as the maple leaf decals, less the maple leaf. I hope this helps some.  Please let me know if I can help with anything else.  Terry.