Hammer Brand Imperial Serpentine Jack Silver pearl Yellow streaks switchblade knife

Vintage Hammer Brand Serpentine Utility Jack switchblade knife from the 1950s. This knife was made by the Imperial Knife Co of Providence, RI and was designated the model JM98PB. The knife measures 3.5 inches closed and 6.25 inches open with brass liners, steel button & safety. The blade is marked HAMMER BRAND USA with a picture of an arm holding a hammer and the back is marked with two patent numbers hard to make out. The clip blade is 99% full with original finish with some faint scratches. The handles (scales) are hollow steel with celluloid wrap in Silver Pearl with yellow streaks. The wraps are in great condition with slight shrinkage. The knife works GREAT with the blade tip seating deep when closed, strong snap and excellent lockup open with just a hint of movement at the tip. Does NOT rattle if shaken with the blade open. Safety works. EX condition.