Press Button Knife Co Business Spear point blade picked bone switchblade knife

Antique Press Button Knife Co Business model picked bone model #500 switchblade knife with less common spear point blade made in Walden, NY sometime between 1892 and 1923. The knife measures 4 1/8" closed and 6 5/8 inches open with steel liners and nickel silver bolsters and button. The spear point blade has some loss from sharpening and has been slightly re-shaped at about 95% full and shiny with light scratches and the tang is stamped PRESS BUTTON KNIFE CO WALDEN, NY and the reverse is stamped US PAT 470605. These PBKC Business models were heavily used, sharpened and carried due to the convenient size so most were worn out, or discarded over the years. The blade was originally acid etched BUSINESS, but the etches were fragile and easily worn off with use. The picked bone scales are in very nice condition. The knife works well with the blade tip below the liners closed, opens fully and locks with less than 1/8" movement either way at the tip open. It rattles if shaken with the blade open as most do after 100 years. VG+ condition.