Gang,
If you look at cranky's photo above you will note one green handle without the white stripe... I believe that is an SK-Wayne, ca. 1962-1968; this would be the beginning of the SK green handles.
The later green and white SK handles are Dresser era ca. 1968-1984/1985, picking up up where SK-Wayne left off and ending in 1985 when the Facom era began and changing to the modern 4-sided solid green handle.