PRESTO single Cigar Tortoise celluloid handle switchblade knife

Vintage PRESTO 3 3/8" single cigar jack with Tortoise celluloid scales (handles) pattern number 610 made by the Geo Schrade Knife Co of Bridgeport, CT most likely between 1930 and 1940. The knife measures 3 3/8" closed and 5 7/8 inches open with brass liners and steel button with nickel silver safety. The clip blade is stamped PRESTO PAT PEND-G  on the tang and backside is stamped G SCHRADE in an arch over B'PORT CT. The clip blade is 97% full and has been lightly sharpened with heavy patina, light scratches and some spotting. The Tortoise celluloid scales are very attractive and in good condition with lots of little scratches from handling. This knife works well with  blade tip below the liners when closed, Good snap, opens fully and locks with less than 1/16" up and down at the tip which is better than average for these knives that have seen a fair amount of use over the past 80 years or so. Safety works. VG condition.