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 1/4 inches open with steel liners, button and safety. The clip 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 blade is 98% full or better and shiny with some light scratches light spotting and a few pepper spots. The jigged bone scales (handles) are in excellent condition. The knife works well with the blade tip even with the liners & centered closed, good snap and good lockup with 1/16" up and down at the tip. No rattle if shaken with blade open. Safety works. EX condition.