These are the LEADER Super-Speed offerings from a 1937-8 Winchester folder --
LEADER Super-Speed listings 1937-8.jpeg
and here are the regular Super-Speed listings from the same folder --
Super-Speed loads 1937-8.jpg
and finally the RANGER listings showing the Handicap Trap Loads with the Kopperklad shot near the bottom.
RANGER loads 1937-8.jpeg
Another thing to note is that Winchester put up the 1 ounce 20-gauge, progressive burning powder, high velocity, load in both a 2 1/2 and a 2 3/4 inch shell, while everyone else only cataloged that load in a 2 3/4 inch or longer shell.
Super-Speed 2 1-2 inch 20-gauge.jpg Super-Speed 2 3-4 inch 20-gauge.jpg