Pre-WW-II you could get a Model 21 "Trap Grade" that was not a trap gun, but a Skeet Gun was always a skeet gun.
My earliest Winchester catalogue to show the Model 21 is 1933. It shows the "Standard", "Tournament", "Trap" and "Custom Built" Grades and the "Skeet Gun". The "Skeet Gun" was offered in 12-, 16-, and 20-gauges with a straight grip stock, checkered wood butt, beavertail forearm, single-selective trigger, ejectors, a non-automatic safety and was bored WS-1 right and WS-2 left. The catalogue goes on to state that in its first year, 1932, the Model 21 Skket Gun carried the long run record in both 12- and 20-gauges.
By the 1934 catalogue you could get a skeet gun in the "Trap" Grade ($147.10) or "Tournament" Grade ($130.70) and you could now have a straight or a pistol grip. By 1938 the "Tournament" Grade is gone, and it is again just the Skeet Gun, but it can be had in "Standard", "Trap" or "Custom Built" Grades, barrels are still only 26-inch but the extra cost option of a vent rib is now available. For 1939, 1940, 1941 and 1946 the offerings were the same. By 1950 the Skeet Gun now has 28-inch barrels, and the remained so through 1959.
