CHALLENGE CUT CO double Cocobolo celluloid automatic knife

Vintage CHALLENGE CUT CO double Cocobolo celluloid automatic knife made in Brigeport, CT between 1918 and 1925. The knife measures 3 3/8 inches closed and 7 inches with both blades open and has brass liners and nickel silver buttons and pins. Both blades are nearly full and dark with patina as well as some scratches and spotting. The front tang on both blades is stamped CHALLENGE CUT CO BRIDGEPORT CONN and rear of large blade stamped FLY-LOCK in an arch and small blade US PAT MARCH 5, 1918. Cocobolo celluloid scales are very nice. Works well with both blade tips below liners closed, both open fully and above average lockup with a little movement each way. Rattles if shaken with blades open. VG+ condition.