PRESTO #6000S Fishtail Jigged Bone scales Vintage switchblade knife

Vintage Presto fishtail switchblade made by the Geo Schrade Knife Co of Bridgeport, CT sometime between 1929 and 1956 and designated the model #6000S. It measures 4 inches closed and 7 1/8 inches open with steel liners & button with nickel silver safety. The blade is marked PRESTO MADE IN USA on the front and G SCHRADE in an arch over B'PORT, CT on the rear tang which means it was an earlier knife, likely made before 1940. The clip blade is 98% full or better with light patina with some light scratches and nice overall. The jigged bone scales (handles) are in excellent condition. The knife works well with the blade tip deep & centered closed, good snap and very good lockup with less than 1/16" up and down at the tip. No rattle if shaken with blade open. Safety works. EX condition.