PRESTO Fishtail #6000 Cocobolo celluloid 1940s vintage switchblade knife

Vintage Presto fishtail switchblade made by the Geo Schrade Knife Co of Bridgeport, CT sometime between 1940 and 1956. This knife was designated the model #6000. It measures 4 inches closed and 7.25 inches open with steel liners, button & 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 so it was likely made before 1950. The carbon steel clip blade is 99% full with patina and some light spotting, very nice blade. The Cocobolo woodgrain celluloid scales (handles) are in good condition with some minor handling marks & scuffs from use over the years, a hairline crack near the bottom of the back scale and lightly carved initials in the back scale looks like an "M" or "W" and something else. Could be lightly sanded out. The knife works well with the blade tip deep & centered closed, good snap and excellent lockup open with less than 1/16" movement at the tip. Button presses a little hard. Does not rattle if shaken when open. Safety works. VG+ condition.