Similar to Double Automatic, except has aircraft aluminum alloy frame color-anodized in blue, silver, green, brown or black. Red-, gold- or royal blue-colored receivers were rarest colors and would command approximately 50 to 75 percent premium. Offered with plain or ventilated rib barrel. Approximately 65,000 produced between 1954 and 1972. NOTE: Add 25 percent for ventilated rib.