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

Antique Press Button Knife Co Invincible picked bone model #1000 switchblade knife with less common spear point blade made in Walden, NY sometime between 1892 and 1923. The knife measures 4 7/8" closed and 8 5/8 inches open with steel liners and nickel silver bolsters , button & pins. The spear point blade has some loss from sharpening and is about 92% full  with light scratches and scattered pitting and the tang is stamped PRESS BUTTON KNIFE CO WALDEN, NY and the reverse is blank. The blade was originally acid etched INVINCIBLE, 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 deep & centered closed, opens fully and locks with less than 1/16" up and down and slightly more side to side at the tip open. It rattles if shaken with the blade open as most do after 100 years. VG condition.